本實驗室以先前開發的3,5-雙取代-N-叔亮胺酸之手性氧釩錯合物，藉由頻哪醇硼烷 (pinacolborane, HBpin) 及兒茶酚硼烷(catecolborane, HBcat) 不對稱催化還原 α-酮基醯胺，擁有不錯的效率。在十二種不同溶劑及六種不同的C3、C5取代的催化劑中，以C3為叔丁基取代，C5為溴取代的氧釩錯合物 1a’，在 −20 ℃ 下以甲苯為溶劑可得到最佳結果。在使用高效的頻哪醇硼烷作為不對稱催化還原試劑，得到產率 44–90% ，鏡像選擇性74–94% (R)；若使用兒茶酚硼烷作為不對稱催化還原試劑，則可得到產率 69–99%，鏡像選擇性60–90% (S)。在預測的過度態中，α-酮基醯胺會因為酮類的羰基與醯胺的氫形成分子內氫鍵，而呈現s-trans構型。因此，頻哪醇硼烷的氫陰離子會從酮類的Si-face攻打，進而還原成R-構型的醇類產物。相反的，因為兒茶酚硼烷的苯環與受質的苯甲醯基片段會產生 π-π 交互作用力，受質會傾向s-cis構型，進而生成S構型的醇類產物。
在第二部分中，我們將受質改為 N-苯甲基-β-酮基醯胺。在九種不同溶劑、三種不同的醇類添加物及四種不同的C3、C5取代的催化劑中，以C3為 2,5-二甲基苯基取代，C5為溴取代的水楊酸衍生之氧釩錯合物 1d，在 −20 ℃ 下以四氫呋喃為溶劑，以頻哪醇硼烷作為還原劑，並搭配叔丁醇做為添加物可得到最佳結果。對應的β-S-羥基醯胺產物，得到產率43–92% ，鏡像選擇性79–99% 。而合成可做為度洛西汀的前驅物，亦可得到產率45% 及鏡像選擇性90% 。對此我們提出兩種還原的過渡態。在模型一中，立體障礙大的頻哪醇硼烷會鍵結在與釩相連接的甲氧基上，並從Re-face提供氫陰離子，得到S構型的醇類產物。另一方面，在模型二中，頻哪醇硼烷會先與V=O鍵結作用，使得氫陰離子從Re-face攻擊在赤道向與釩鍵結的羰基，得到S-構型的醇類產物。
在最後一部分，我們將受質延伸為α-甲基-β-酮基醯胺。在十種不同溶劑、五種不同的添加物及九種不同的C3、C5取代的催化劑中，以氧釩錯合物 1d，在 −20 ℃ 下以等比例之四氫呋喃-丙酮混合溶劑，頻哪醇硼烷作為還原劑，可得到最佳結果為產率70% 、鏡像選擇性91% 及非對映異構選擇性99：1 (同向:反向)。此外，在更具挑戰性的受質α-苯基-β-酮基醯胺，其還原產物α-苯基-β-羥基醯胺得到產率66% 及鏡像選擇性89% 。我們預測以上兩種受質與β-酮基醯胺有類似的過渡態，頻哪醇硼烷會與釩相連接的甲氧基或V=O鍵結作用，使得氫陰離子從Re-face攻擊在赤道向與釩鍵結的羰基，得到高度同向選擇性之α-甲基(或苯基)-β-羥基醯胺。

We have developed an efficient system for the complementary asymmetric reduction of α-ketobenzylamide with pinacolborane (HBPin) and catecholborane (HBCat) catalyzed by chiral oxo-vanadium (V) methoxides complexes derived from 3,5-disubstituted-N-salicylidene-tert-leucine. Among twelve different solvents and six different C-3, C-5 substituted catalysts examined, the use of C3 t-butyl and C-5 Br (1a') catalyst in toluene at −20 °C afforded the best results. An efficient reagent based complementary enantioselective reduction was afforded in 44–90% yield with 74–94% R-isomer using HBPin and 69–99% yield with 60–90% S-isomer using HBCat. In the proposed transition state, the α-ketoamide adopted an s-trans conformation with an internal H-bonding between the ketone carbonyl and the amide H so that the bulky pinacolborane would deliver the hydride from Si-face of the ketone moiety to give the resulting alcohol in R-configuration. Conversely, an s-cis conformation would be preferred in the reduction by catecholborane in view of the favourable - interaction between the benzoyl unit in the substrate and the benzene ring in HBCat to give the resulting alcohol in S-configuration.
In Part 2, we changed the substrate class to N-benzyl-β-ketoamides. Among nine different solvents, three different alcohol additives, and four different catalysts examined, the use of 1d complex bearing 3-(2,5-dimethylphenyl),5-Br on salicylidene template and HBPin as reducing agent in tetrahydrofuran (THF) with a t-BuOH additive led to the best results at −20 °C. The corresponding β-S-hydroxyamides furnished with 43–92% yields and 79–99% ees. A precursor to duloxetine drug has been synthesized in 45% yield and 90 % ee. Two reductant-directed favourable transition state has been proposed, in mode I the bulky HBPin directed by vanadyl bound methoxide delivered the hydride from re face to give S-configuration alcohol. On the other hand, in mode II the HBPin first interact with V=O followed by re face attack on equatorially coordinated carbonyl to give S-configuration alcohol.
In final part, we further extended the substrate class to α-methyl-β-keto amide. A thorough screening of ten solvents, five additives and nine different catalysts afforded the highly desymmetric α-methyl-β-hydroxy amide in 70% yield with 91% ee and 99:1 dr (syn:anti) in THF: acetone (1:1) mixed solvent at −20 °C using HBPin as reducing agent with 1d catalyst. Subsequently, a more challenging α-phenyl-β-ketoamide enantioselectively reduced to syn selective α-phenyl-β-hydroxy amide in 66% yield with 89% ee. A similar plausible transition state has been proposed as that of beta-keto amide, in which bulky HBPin directed by vanadyl bound methoxide or V=O delivered the hydride from re face of carbonyl to give highly syn selective α-methyl/phenyl-β-hydroxy amides.

TABLE OF CONTENTS
Page
中文摘要 i
Abstract iii
Acknowledgement v
Table of contents vii
ABBREVIATIONS xi
List of Publications xiii
CHAPTER 1: Introduction 1
Section 1.1. Vanadium 1
Section 1.2. Application of vanadyl complexes in organic synthesis and catalytic reactions. 1
Section 1.2.1. Asymmetric oxidation of secondary alcohol compounds catalyzed by vanadyl complexes 2
Section 1.2.2 Asymmetric coupling reaction of aromatic phenols catalyzed by vanadyl complexes 5
Section 3: Asymmetric reduction 12
1.3.1. Introduction to reducing agent 12
1.3.2 Chiral Oxazaborolidine asymmetric reduction 13
1.3.3 Asymmetric reduction with transition metal complexes and borohydrides or borane derivatives 17
1.3.4 Asymmetric reduction with transition metal complexes and silane derivatives 26
1.3.5 Asymmetric reduction of keto esters and keto amides 31
Chapter 2 Results and discussions 37
Section 2.1 Asymmetric reduction of alpha keto amides 37
2.1.1 Solvent screening 38
2.1.2 Reducing Agent screening 39
2.1.3 Catalyst Screening 40
2.1.4 Additive and solvent screening 42
2.1.5 Substrate Scope 44
2.1.6 Proposed Transition State: 49
2.1.7 Conclusion 50
Section 2.2 Asymmetric reduction of β-keto amides 51
2.2.1 Reducing agent and Solvent Screening 51
2.2.2 Additive screening 52
2.2.3 Catalyst and further solvent screening 53
2.2.4 Substrate Scope 55
2.2.5 Application
2.2.6. Non-Linear Effect study: 58
59
2.2.7 Proposed transition state 62
2.2.8 Conclusion: 63
Section 2.3 Asymmetric reduction of α-substituted-β-ketoamides 64
2.3.1 Additive screening 64
2.3.2 Solvent screening 65
2.3.3 Catalyst Screening 67
2.3.4 Asymmetric reduction of β-keto-α-phenyl substrate: 70
2.3.5 Proposed transition state 71
2.3.5 Conclusion 72
Materials and Methods: 73
Chapter 3 Experimental Section: 75
3.1. Synthesis and characterization data of oxo-vanadium(V) complexes 1a–1l. 75
3.1.1. Synthetic steps and spectral data of 1a catalyst: 75
3.1.2. Synthetic steps and spectral data of 1a’ catalyst: 78
3.1.3. Synthetic steps and spectral data of 1b catalyst: 80
3.1.4. Synthetic steps and spectral data of 1c catalyst: 81
3.1.5. Synthetic steps and spectral data of 1d catalyst: 80
3.1.6. Synthetic steps and spectral data of 1e catalyst: 85
3.1.7. Synthetic steps and spectral data of 1f catalyst: 88
3.1.8. Synthetic steps and spectral data of 1g catalyst: 89
3.1.9. Synthetic steps and spectral data of 1h catalyst: 91
3.1.10. Synthetic steps and spectral data of 1i catalyst: 93
3.1.11. Synthetic steps and spectral data of 1j catalyst: 96
3.1.13. Synthetic steps and spectral data of 1k catalyst: 99
3.1.14. Synthetic steps and spectral data of 1l catalyst: 102
3.2. Synthetic procedure and characteristic data of α-keto amides: 103
3.2.1 Method (a) 103
3.2.2 Method (b) (3b–r) 103
3.3. Reaction procedure for the asymmetric reduction of N-benzyl-α-keto-amides. 109
3.4. General synthetic schemes for the preparation of β-keto amides. 118
3.4.1 Method-a: 118
3.4.2 Method-b: 119
3.4.3 Method-c: 120
3.4.4 Synthesis of N-methyl-3-oxo-3-(thiophen-2-yl)propanamide: 121
3.4.5 Synthesis of N-benzyl-3-oxo-5-phenylpentanamide: 122
3.5. General reaction procedure for the asymmetric reduction of β-keto amides: 123
3.6. Reaction procedure for the synthesis of the (S)-duloxetine precursor: (S)-3-hydroxy-N-methyl-3-(thiophen-2-yl)propanamide: 124
3.7. General procedure for deuterium exchange reaction: 124
3.8. Characterization data of the β-keto amide substrates and products: 125
3.9 Procedure for 2 mmol Scale preparation of (S)-N-Benzyl-3-(4-chlorophenyl)-3-hydroxypropanamide (5d): 140
3.10. Synthetic procedure for for N-benzyl-α-methyl/phenyl-β-keto amides 142
Method a: 142
Method b: 143
3.11. Reaction procedure for the synthesis of racemic α-methyl-β-hydroxy amides: 144
3.12. Reaction procedure for the synthesis of racemic α-phenyl-β-hydroxy amides: 144
3.13. General reaction procedure for the asymmetric reduction of α-methyl-β-keto amides: 145
3.14. Reaction procedure for the asymmetric reduction of α-phenyl-β-keto amides: 146
References 148
HPLC Chromatograms S1
NMR Spectra S43
X-ray Data S269

1. Cotton, F. A. W., G.; Murillo, C. A.; Bochmann, M. Advanced Inorganic Chemistry,, 6th ed.; John Wiley & Sons: New York,. 1999.
2. Weeks, M. E., The discovery of the elements. XVII. The halogen family. J. Chem. Educ. 1932, 9, 1915.
3. Helder, R.; Hummelen, J. C.; Laane, R. W. P. M.; Wiering, J. S.; Wynberg, H., Catalytic asymmetric induction in oxidation reactions. The synthesis of optically active epoxides. Tetrahedron Lett. 1976, 17, 1831–1834.
4. Michaelson, R. C.; Palermo, R. E.; Sharpless, K. B., Chiral hydroxamic acids as ligands in the vanadium catalyzed asymmetric epoxidation of allylic alcohols by tert-butyl hydroperoxide. J. Am. Chem. Soc. 1977, 99, 1990–1992.
5. Murase, N.; Hoshino, Y.; Oishi, M.; Yamamoto, H., Chiral Vanadium-Based Catalysts for Asymmetric Epoxidation of Allylic Alcohols. J. Org. Chem. 1999, 64, 338–339.
6. Hoshino, Y.; Yamamoto, H., Novel α-Amino Acid-Based Hydroxamic Acid Ligands for Vanadium-Catalyzed Asymmetric Epoxidation of Allylic Alcohols. J. Am. Chem. Soc. 2000, 122, 10452–10453.
7. Zhang, W.; Basak, A.; Kosugi, Y.; Hoshino, Y.; Yamamoto, H., Enantioselective Epoxidation of Allylic Alcohols by a Chiral Complex of Vanadium: An Effective Controller System and a Rational Mechanistic Model. Angew. Chem., Int. Ed. 2005, 44, 4389–4391.
8. Zhang, W.; Yamamoto, H., Vanadium-Catalyzed Asymmetric Epoxidation of Homoallylic Alcohols. J. Am. Chem. Soc. 2007, 129, 286–287.
9. Li, Z.; Zhang, W.; Yamamoto, H., Vanadium-Catalyzed Enantioselective Desymmetrization of meso Secondary Allylic Alcohols and Homoallylic Alcohols. Angew. Chem., Int. Ed. 2008, 47, 7520–7522.
10. Wu, H.-L.; Uang, B.-J., Asymmetric epoxidation of allylic alcohols catalyzed by new chiral vanadium(V) complexes. Tetrahedron: Asymmetry 2002, 13, 2625–2628.
11. Bourhani, Z.; Malkov, A. V., Ligand-accelerated vanadium-catalysed epoxidation in water. Chem. Commun. 2005, 4592–4594.
12. Noji, M.; Kobayashi, T.; Uechi, Y.; Kikuchi, A.; Kondo, H.; Sugiyama, S.; Ishii, K., Asymmetric Epoxidation of Allylic Alcohols Catalyzed by Vanadium–Binaphthylbishydroxamic Acid Complex. J. Org. Chem. 2015, 80, 3203–3210.
13. Han, L.; Liu, C.; Zhang, W.; Shi, X.-X.; You, S.-L., Dearomatization of tryptophols via a vanadium-catalyzed asymmetric epoxidation and ring-opening cascade. Chem. Commun. 2014, 50, 1231–1233.
14. Han, L.; Zhang, W.; Shi, X.-X.; You, S.-L., Dearomatization of Indoles via a Phenol-Directed Vanadium- Catalyzed Asymmetric Epoxidation and Ring-Opening Cascade. Adv. Synth. Catal. 2015, 357, 3064–3068.
15. Fernández, I.; Khiar, N., Recent Developments in the Synthesis and Utilization of Chiral Sulfoxides. Chem. Rev. 2003, 103, 3651–3706.
16. Remuzzi, G.; Perico, N.; Benigni, A., New therapeutics that antagonize endothelin: promises and frustrations. Nat. Rev. Drug Discovery 2002, 1, 986–1001.
17. Curci, R.; Di Furia, F.; Testi, R.; Modena, G., Metal catalysis in oxidation by peroxides. Vanadium catalysed oxidation of organosulphur compounds by t-butyl hydroperoxide. J. Chem. Soc., Perkin Trans. 2 1974, 752–757.
18. Kiyohiko, N.; Masaaki, K.; Junnosuke, F., Asymmetric Oxidation of Sulfides to Sulfoxides by Organic Hydroperoxides with Optically Active Schiff Base-Oxovanadium(IV) Catalysts. Chem. Lett. 1986, 15, 1483–1486.
19. Bolm, C.; Bienewald, F., Asymmetric Sulfide Oxidation with Vanadium Catalysts and H2O2. Angew. Chem., Int. Ed. 1996, 34, 2640–2642.
20. Sun, J.; Zhu, C.; Dai, Z.; Yang, M.; Pan, Y.; Hu, H., Efficient Asymmetric Oxidation of Sulfides and Kinetic Resolution of Sulfoxides Catalyzed by a Vanadium−Salan System. J. Org. Chem. 2004, 69, 8500–8503.
21. Drago, C.; Caggiano, L.; Jackson, R. F. W., Vanadium-Catalyzed Sulfur Oxidation/Kinetic Resolution in the Synthesis of Enantiomerically Pure Alkyl Aryl Sulfoxides. Angew. Chem., Int. Ed. 2005, 44, 7221–7223.
22. Liu, H.; Wang, M.; Wang, Y.; Wang, Y.; Sun, H.; Sun, L., Asymmetric oxidation of sulfides with hydrogen peroxide catalyzed by a vanadium complex of a new chiral NOO-ligand. Catal. Commun. 2009, 11, 294–297.
23. Zeng, Q.; Gao, Y.; Dong, J.; Weng, W.; Zhao, Y., Vanadium-catalyzed enantioselective oxidation of allyl sulfides. Tetrahedron: Asymmetry 2011, 22, 717–721.
24. Zeng, Q.; Weng, W.; Xue, X., Sulfide oxidation catalyzed vanadyl complexes of N-salicylidene α-amino acids at low catalyst loading. Inorg. Chim. Acta 2012, 388, 11–15.
25. Chuo, T. H.; Boobalan, R.; Chen , C., Camphor-Based Schiff Base Of 3-Endo-Aminoborneol (SBAB): Novel Ligand for Vanadium-Catalyzed Asymmetric Sulfoxidation and Subsequent Kinetic Resolution. ChemistrySelect 2016, 1, 2174–2180.
26. Ben Zid, T.; Fadhli, M.; Khedher, I.; Fraile, J. M., New bis(oxazoline)–vanadyl complexes, supported by electrostatic interaction in Laponite clay, as heterogeneous catalysts for asymmetric oxidation of methyl phenyl sulfide. Microporous Mesoporous Mater. 2017, 239, 167–172.
27. Radosevich, A.; Musich, C.; Toste, F., Vanadium-Catalyzed Asymmetric Oxidation of α-Hydroxy Esters Using Molecular Oxygen as Stoichiometric Oxidant. J. Am. Chem. Soc. 2005, 127, 1090–1.
28. Shiels, R. A.; Venkatasubbaiah, K.; Jones, C. W., Polymer and Silica Supported Tridentate Schiff Base Vanadium Catalysts for the Asymmetric Oxidation of Ethyl Mandelate – Activity, Stability and Recyclability. Adv. Synth. Catal. 2008, 350, 2823–2834.
29. Weng, S.-S.; Shen, M.-W.; Kao, J.-Q.; Munot, Y. S.; Chen, C.-T., Chiral N-salicylidene vanadyl carboxylate-catalyzed enantioselective aerobic oxidation of α-hydroxy esters and amides. Proc. Natl. Acad. Sci. U. S. A. 2006, 103, 3522–3527.
30. Pawar, V. D.; Bettigeri, S.; Weng, S.-S.; Kao, J.-Q.; Chen, C.-T., Highly Enantioselective Aerobic Oxidation of α-Hydroxyphosphonates Catalyzed by Chiral Vanadyl(V) Methoxides Bearing N-Salicylidene-α-aminocarboxylates. J. Am. Chem. Soc. 2006, 128, 6308–6309.
31. Chen, C. T.; Kao, J. Q.; Salunke, S. B.; Lin, Y. H., Enantioselective aerobic oxidation of α-hydroxy-ketones catalyzed by oxidovanadium(V) methoxides bearing chiral, N-salicylidene-tert-butylglycinates. Org. Lett. 2011, 13, 26–9.
32. Salunke, S. B.; Babu, N. S.; Chen, C.-T., Asymmetric Aerobic Oxidation of α-Hydroxy Acid Derivatives Catalyzed by Reusable, Polystyrene-Supported Chiral N-Salicylidene Oxidovanadium tert-Leucinates. Adv. Synth. Catal. 2011, 353, 1234–1240.
33. Hwang, D.-R.; Chen, C.-P.; Uang, B.-J., Aerobic catalytic oxidative coupling of 2-naphthols and phenols by VO(acac)2. Chem. Commun. 1999, 1207–1208.
34. Hon, S.-W.; Li, C.-H.; Kuo, J.-H.; Barhate, N. B.; Liu, Y.-H.; Wang, Y.; Chen, C.-T., Catalytic Asymmetric Coupling of 2-Naphthols by Chiral Tridentate Oxovanadium(IV) Complexes. Org. Lett. 2001, 3, 869–872.
35. Chu, C.-Y.; Hwang, D.-R.; Wang, S.-K.; Uang, B.-J., Chiral oxovanadium complex catalyzed enantioselective oxidative coupling of 2-naphthols. Chem. Commun. 2001, 980–981.
36. Barhate, N. B.; Chen, C.-T., Catalytic Asymmetric Oxidative Couplings of 2-Naphthols by Tridentate N-Ketopinidene-Based Vanadyl Dicarboxylates. Org. Lett. 2002, 4, 2529–2532.
37. Luo, Z.; Liu, Q.; Gong, L.; Cui, X.; Mi, A.; Jiang, Y., The rational design of novel chiral oxovanadium(IV) complexes for highly enantioselective oxidative coupling of 2-naphthols. Chem. Commun. 2002, 914–915.
38. Guo, Q.-X.; Wu, Z.-J.; Luo, Z.-B.; Liu, Q.-Z.; Ye, J.-L.; Luo, S.-W.; Cun, L.-F.; Gong, L.-Z., Highly Enantioselective Oxidative Couplings of 2-Naphthols Catalyzed by Chiral Bimetallic Oxovanadium Complexes with Either Oxygen or Air as Oxidant. J. Am. Chem. Soc. 2007, 129, 13927–13938.
39. Takizawa, S.; Katayama, T.; Sasai, H., Dinuclear chiral vanadium catalysts for oxidative coupling of 2-naphthols via a dual activation mechanism. Chem. Commun. 2008, 4113–4122.
40. Takizawa, S.; Kodera, J.; Yoshida, Y.; Sako, M.; Breukers, S.; Enders, D.; Sasai, H., Enantioselective oxidative-coupling of polycyclic phenols. Tetrahedron 2014, 70, 1786–1793.
41. (a) Sako, M.; Takizawa, S.; Yoshida, Y.; Sasai, H., Enantioselective and aerobic oxidative coupling of 2-naphthol derivatives using chiral dinuclear vanadium(V) complex in water. Tetrahedron: Asymmetry 2015, 26, 613–616; (b) Sako, M.; Takeuchi, Y.; Tsujihara, T.; Kodera, J.; Kawano, T.; Takizawa, S.; Sasai, H., Efficient Enantioselective Synthesis of Oxahelicenes Using Redox/Acid Cooperative Catalysts. J. Am. Chem. Soc. 2016, 138, 11481–11484.
42. (a) Narute, S.; Parnes, R.; Toste, F. D.; Pappo, D., Enantioselective Oxidative Homocoupling and Cross-Coupling of 2-Naphthols Catalyzed by Chiral Iron Phosphate Complexes. J. Am. Chem. Soc. 2016, 138, 16553–16560; (b) Narute, S.; Pappo, D., Iron Phosphate Catalyzed Asymmetric Cross-Dehydrogenative Coupling of 2-Naphthols with β-Ketoesters. Org. Lett. 2017, 19, 2917–2920.
43. Shende, V. S.; Singh, P.; Bhanage, B. M., Recent trends in organocatalyzed asymmetric reduction of prochiral ketones. Catal. Sci. Technol. 2018, 8, 955–969.
44. Borch, R. F.; Levitan, S. R., Asymmetric synthesis of alcohols, amines, and amino acids. J. Org. Chem. 1972, 37, 2347–2349.
45. Hirao, A.; Itsuno, S.; Nakahama, S.; Yamazaki, N., Asymmetric reduction of aromatic ketones with chiral alkoxy-amineborane complexes. J. Chem. Soc. Chem. Commun. 1981, 315–317.
46. Itsuno, S.; Ito, K.; Hirao, A.; Nakahama, S., Asymmetric reduction of aromatic ketones with the reagent prepared from (S)-(–)-2-amino-3-methyl-1,1-diphenylbutan-1-ol and borane. J. Chem. Soc. Chem. Commun. 1983, 469–470.
47. Corey, E. J.; Bakshi, R. K.; Shibata, S., Highly enantioselective borane reduction of ketones catalyzed by chiral oxazaborolidines. Mechanism and synthetic implications. J. Am. Chem. Soc. 1987, 109, 5551–5553.
48. Kaldun, J.; Krimalowski, A.; Breuning, M., Enantioselective borane reduction of ketones catalyzed by tricyclic 1,3,2-oxazaborolidines. Tetrahedron Lett. 2016, 57, 2492–2495.
49. Azizoglu, M.; Erdogan, A.; Arslan, N.; Turgut, Y.; Hosgoren, H.; Pirinccioglu, N., A series of novel β-hydroxyamide based catalysts for borane-mediated enantioselective reductions of prochiral ketones. Tetrahedron: Asymmetry 2016, 27, 614–622.
50. Nagata, T.; Yorozu, K.; Yamada, T.; Mukaiyama, T., Enantioselective Reduction of Ketones with Sodium Borohydride, Catalyzed by Optically Active (β-Oxoaldiminato)cobalt(II) Complexes. Angew. Chem., Int. Ed. 1995, 34, 2145–2147.
51. D., S. K.; Takushi, N.; Tohru, Y.; Teruaki, M., Enantioselective Borohydride Reduction of Ketones Catalyzed by Optically Active Cobalt(II) Complexes: Achievement of High Enantioselection by Modified Borohydrides with Furfuryl Alcohol Derivatives. Chem. Lett. 1996, 25, 737–738.
52. Ohtsuka, Y.; Koyasu, K.; Ikeno, T.; Yamada, T., Reductive desymmetrization of 2-alkyl-1,3-diketones catalyzed by optically active beta-ketoiminato cobalt complexes. Org. Lett. 2001, 3, 2543–6.
53. Tsubo, T.; Chen, H.-H.; Yokomori, M.; Fukui, K.; Kikuchi, S.; Yamada, T., Enantioselective Borohydride Reduction of Aliphatic Ketones Catalyzed by Ketoiminatocobalt(III) Complex with 1-Chlorovinyl Axial Ligand. Chem. Lett. 2012, 41, 780–782.
54. Tsubo, T.; Chen, H.-H.; Yokomori, M.; Kikuchi, S.; Yamada, T., Reusable Cobalt(III) Complex Catalysts for Enantioselective Borohydride Reduction of Ketones. Bull. Chem. Soc. Jpn. 2013, 86, 983–986.
55. Giffels, G.; Dreisbach, C.; Kragl, U.; Weigerding, M.; Waldmann, H.; Wandrey, C., Chiral Titanium Alkoxides as Catalysts for the Enantioselective Reduction of Ketones with Boranes. Angew. Chem., Int. Ed. 1995, 34, 2005–2006.
56. Almqvist, F.; Torstensson, L.; Gudmundsson, A.; Frejd, T., New Ligands for the Titanium (IV)-Induced Asymmetric Reduction of Ketones with Catecholborane. Angew. Chem., Int. Ed. 1997, 36, 376–377.
57. (a) Vogels, C. M.; O'Connor, P. E.; Phillips, T. E.; Watson, K. J.; Shaver, M. P.; Hayes, P. G.; Westcott, S. A., Rhodium-catalyzed hydroborations of allylamine and allylimines1. Can. J. Chem. 2001, 79, 1898–1905; (b) Friberg, A.; Sarvary, I.; Wendt, O. F.; Frejd, T., Bicyclo[2.2.2]octane-derived chiral ligands—synthesis and application of BODOLs in the asymmetric reduction of acetophenone with catecholborane. Tetrahedron: Asymmetry 2008, 19, 1765–1777.
58. Phothongkam, S.; Uang, B.-J., Enantioselective Reduction of Ketones Induced by a C2-Symmetrical Chiral Hydroxyamide/Titanium(IV) complex. Asian J. Chem. 2015, 4, 794–799.
59. Fu-Yao, Z.; Chiu-Wing, Y.; Chan, A. S. C., Enantioselective borane reduction of ketones catalyzed by chiral lanthanum alkoxides. Tetrahedron: Asymmetry 1996, 7, 2463–2466.
60. Lin, Y.-M.; Fu, I. P.; Uang, B.-J., Enantioselective borane reduction of aromatic ketones using chiral BINOL derivatives as ligands in an aluminum catalyst. Tetrahedron: Asymmetry 2001, 12, 3217–3221.
61. Vasilenko, V.; Blasius, C. K.; Wadepohl, H.; Gade, L. H., Mechanism-Based Enantiodivergence in Manganese Reduction Catalysis: A Chiral Pincer Complex for the Highly Enantioselective Hydroboration of Ketones. Angew. Chem., Int. Ed. 2017, 56, 8393–8397.
62. Nishiyama, H.; Kondo, M.; Nakamura, T.; Itoh, K., Highly enantioselective hydrosilylation of ketones with chiral and C2-symmetrical bis(oxazolinyl)pyridine-rhodium catalysts. Organometallics 1991, 10, 500–508.
63. Shaikh, N. S.; Enthaler, S.; Junge, K.; Beller, M., Iron-Catalyzed Enantioselective Hydrosilylation of Ketones. Angew. Chem., Int. Ed. 2008, 47, 2497–2501.
64. Nolin, K. A.; Ahn, R. W.; Toste, F. D., Enantioselective Reduction of Imines Catalyzed by a Rhenium(V)−Oxo Complex. J. Am. Chem. Soc. 2005, 127, 12462–12463.
65. Nolin, K. A.; Ahn, R. W.; Kobayashi, Y.; Kennedy-Smith, J. J.; Toste, F. D., Enantioselective Reduction of Ketones and Imines Catalyzed by (CN-Box)ReV–Oxo Complexes. Chem.Eur. J. 2010, 16, 9555–9562.
66. Das, B. G.; Nallagonda, R.; Dey, D.; Ghorai, P., Synthesis of Air- and Moisture-Stable, Storable Chiral Oxorhenium Complexes and Their Application as Catalysts for the Enantioselective Imine Reduction. Chem.Eur. J. 2015, 21, 12601–12605.
67. (a) Schiwek, C. H.; Vasilenko, V.; Wadepohl, H.; Gade, L. H., The open d-shell enforces the active space in 3d metal catalysis: highly enantioselective chromium(II) pincer catalysed hydrosilylation of ketones. Chem. Commun. 2018, 54, 9139–9142; (b) Titze, M.; Heitkämper, J.; Junge, T.; Kästner, J.; Peters, R., Highly Active Cooperative Lewis Acid—Ammonium Salt Catalyst for the Enantioselective Hydroboration of Ketones. Angew. Chem., Int. Ed. 2021, 60, 5544–5553.
68. (a) Asao, N.; Asano, T.; Yamamoto, Y., Do More Electrophilic Aldehydes/Ketones Exhibit Higher Reactivity toward Nucleophiles in the Presence of Lewis Acids? Angew. Chem., Int. Ed. 2001, 40, 3206–3208; (b) Verkade, J. M. M.; Quaedflieg, P. J. L. M.; Verzijl, G. K. M.; Lefort, L.; van Delft, F. L.; de Vries, J. G.; Rutjes, F. P. J. T., Enantio- and diastereoselective synthesis of γ-amino alcohols. Chem. Commun. 2015, 51, 14462–14464; (c) Zuo, W.; Morris, R. H., Synthesis and use of an asymmetric transfer hydrogenation catalyst based on Iron(II) for the synthesis of enantioenriched alcohols and amines. Nat. Protoc. 2015, 10, 241–257; (d) Kong, D.; Li, M.; Wang, R.; Zi, G.; Hou, G., Asymmetric Hydrogenation of β-Aryloxy/Alkoxy Cinnamic Nitriles and Esters. Org. Lett. 2016, 18, 4916–4919; (e) Štefane, B.; Požgan, F., Metal-Catalysed Transfer Hydrogenation of Ketones. Top. Curr. Chem. 2016, 374, 18; (f) Chen, J.; Zhang, T.; Liu, X.; Shen, L., Enantioselective Synthesis of (S)-γ-Amino Alcohols by Ru/Rh/Ir Catalyzed Asymmetric Transfer Hydrogenation (ATH) with Tunable Chiral Tetraaza Ligands in Water. Catal. Lett. 2019, 149, 601–609; (g) Gao, T.-T.; Zhang, W.-W.; Sun, X.; Lu, H.-X.; Li, B.-J., Stereodivergent Synthesis through Catalytic Asymmetric Reversed Hydroboration. J. Am. Chem. Soc. 2019, 141, 4670–4677.
69. (a) Enders, D.; Stöckel, B. A.; Rembiak, A., Enantio- and chemoselective Brønsted-acid/Mg(nBu)2 catalysed reduction of α-keto esters with catecholborane. Chem. Commun. 2014, 50, 4489–4491; (b) Mamillapalli, N. C.; Sekar, G., Enantioselective Synthesis of α-Hydroxy Amides and β-Amino Alcohols from α-Keto Amides. Chem.Eur. J. 2015, 21, 18584–18588.
70. Gu, G.; Yang, T.; Yu, O.; Qian, H.; Wang, J.; Wen, J.; Dang, L.; Zhang, X., Enantioselective Iridium-Catalyzed Hydrogenation of α-Keto Amides to α-Hydroxy Amides. Org. Lett. 2017, 19, 5920–5923.
71. Zhang, L.; Wang, Z.; Han, Z.; Ding, K., Manganese-Catalyzed anti-Selective Asymmetric Hydrogenation of α-Substituted β-Ketoamides. Angew. Chem., Int. Ed. 2020, 59, 15565–15569.
72. (a) Kühn, F. E.; Santos, A. M.; Abrantes, M., Mononuclear Organomolybdenum(VI) Dioxo Complexes:  Synthesis, Reactivity, and Catalytic Applications. Chem. Rev. 2006, 106, 2455–2475; (b) Chakravarthy, R. D.; Chand, D. K., Synthesis, structure and applications of [cis-dioxomolybdenum(VI)-(ONO)] type complexes. J. Chem. Sci. 2011, 123, 187–199; (c) Zwettler, N.; Schachner, J. A.; Belaj, F.; Mösch-Zanetti, N. C., Oxorhenium(V) Complexes with Phenolate–Pyrazole Ligands for Olefin Epoxidation Using Hydrogen Peroxide. Inorg. Chem. 2014, 53, 12832–12840; (d) Liu, Y.; Lau, T.-C., Activation of Metal Oxo and Nitrido Complexes by Lewis Acids. J. Am. Chem. Soc. 2019, 141, 3755–3766.
73. Fernandes, A. C.; Fernandes, R.; Romão, C. C.; Royo, B., [MoO2Cl2] as catalyst for hydrosilylation of aldehydes and ketones. Chem. Commun. 2005, 213–214.
74. (a) Chen, C.-T.; Lin, J.-S.; Kuo, J.-H.; Weng, S.-S.; Cuo, T.-S.; Lin, Y.-W.; Cheng, C.-C.; Huang, Y.-C.; Yu, J.-K.; Chou, P.-T., Site-Selective DNA Photocleavage Involving Unusual Photoinitiated Tautomerization of Chiral Tridentate Vanadyl(V) Complexes Derived from N-Salicylidene α-Amino Acids. Org. Lett. 2004, 6, 4471–4474; (b) Chen, C.-T.; Lin, Y.-H.; Kuo, T.-S., Directed Assembly of Chiral Oxidovanadium(V) Methoxides into C4-Symmetric Metal(I) Vanadate-Centered Quadruplexes: Synergistic K+- and Ag+-specific Transport. J. Am. Chem. Soc. 2008, 130, 12842–12843.
75. (a) Pujol, A.; Calow, A. D. J.; Batsanov, A. S.; Whiting, A., One-pot catalytic asymmetric borylation of unsaturated aldehyde-derived imines; functionalisation to homoallylic boronate carboxylate ester derivatives. Org. Biomol. Chem. 2015, 13, 5122–5130; (b) Hendi, S. B.; Hendi, M. S.; Wolfe, J. F., A New Synthesis of β-Keto Amides via Reaction of Ketone Lithium Enolates with Isocyanates. Synth. Commun. 1987, 17, 13–18; (c) Tang, C. G.; Lin, H.; Zhang, C.; Liu, Z. Q.; Yang, T.; Wu, Z. L., Highly enantioselective bioreduction of N-methyl-3-oxo-3-(thiophen-2-yl) propanamide for the production of (S)-duloxetine. Biotechnol. Lett. 2011, 33, 1435–1440; (d) Ren, Z.-Q.; Liu, Y.; Pei, X.-Q.; Wang, H.-B.; Wu, Z.-L., Bioreductive production of enantiopure (S)-duloxetine intermediates catalyzed with ketoreductase ChKRED15. J. Mol. Catal. B: Enzym. 2015, 113, 76–81.
76. (a) Wynberg, H.; Feringa, B., Enantiomeric recognition and interactions. Tetrahedron 1976, 32, 2831–2834; (b) Puchot, C.; Samuel, O.; Dunach, E.; Zhao, S.; Agami, C.; Kagan, H. B., Nonlinear effects in asymmetric synthesis. Examples in asymmetric oxidations and aldolization reactions. J. Am. Chem. Soc. 1986, 108, 2353–2357; (c) Girard, C.; Kagan, H. B., Nonlinear Effects in Asymmetric Synthesis and Stereoselective Reactions: Ten Years of Investigation. Angew. Chem., Int. Ed. 1998, 37, 2922–2959; (d) Finn, M. G.; Sharpless, K. B., Mechanism of asymmetric epoxidation. 2. Catalyst structure. J. Am. Chem. Soc. 1991, 113, 113–126; (e) Satyanarayana, T.; Abraham, S.; Kagan, H. B., Nonlinear Effects in Asymmetric Catalysis. Angew. Chem., Int. Ed. 2009, 48, 456–494.
77. (a) Shi, S.; Nolan, S. P.; Szostak, M., Well-Defined Palladium(II)–NHC Precatalysts for Cross-Coupling Reactions of Amides and Esters by Selective N–C/O–C Cleavage. Acc. Chem. Res. 2018, 51, 2589–2599; (b) Tan, Q. W.; Chovatia, P.; Willis, M. C., Copper-catalysed synthesis of alkylidene 2-pyrrolinone derivatives from the combination of α-keto amides and alkynes. Org. Biomol. Chem. 2018, 16, 7797–7800.
78. Shin, I.; Lee, M.-R.; Lee, J.; Jung, M.; Lee, W.; Yoon, J., Synthesis of Optically Active Phthaloyl D-Aminooxy Acids from L-Amino Acids or L-Hydroxy Acids as Building Blocks for the Preparation of Aminooxy Peptides. J. Org. Chem. 2000, 65, 7667–7675.
79. Jiang, Y.; Chen, X.; Zheng, Y.; Xue, Z.; Shu, C.; Yuan, W.; Zhang, X., Highly Diastereoselective and Enantioselective Synthesis of α-Hydroxy β-Amino Acid Derivatives: Lewis Base Catalyzed Hydrosilylation of α-Acetoxy β-Enamino Esters. Angew. Chem., Int. Ed. 2011, 50, 7304–7307.
80. Russo, A.; Galdi, G.; Croce, G.; Lattanzi, A., Highly Enantioselective Epoxidation Catalyzed by Cinchona Thioureas: Synthesis of Functionalized Terminal Epoxides Bearing a Quaternary Stereogenic Center. Chem.Eur. J. 2012, 18, 6152–6157.
81. Rostovskii, N. V.; Novikov, M. S.; Khlebnikov, A. F.; Khlebnikov, V. A.; Korneev, S. M., Rh(II)-carbenoid mediated 2H-azirine ring-expansion as a convenient route to non-fused photo- and thermochromic 2H-1,4-oxazines. Tetrahedron 2013, 69, 4292–4301.
82. Kern, N.; Hoffmann, M.; Blanc, A.; Weibel, J.-M.; Pale, P., Gold(I)-Catalyzed Rearrangement of N-Aryl 2-Alkynylazetidines to Pyrrolo[1,2-a]indoles. Org. Lett. 2013, 15, 836–839.
83. Di Grandi, M. J.; Bennett, C.; Cagino, K.; Muccini, A.; Suraci, C.; Saba, S., Direct Preparation of Amides from Amine Hydrochloride Salts and Orthoesters: A Synthetic and Mechanistic Perspective. Synth. Commun. 2015, 45, 2601–2607.
84. Lin, Z.; Li, J.; Huang, Q.; Huang, Q.; Wang, Q.; Tang, L.; Gong, D.; Yang, J.; Zhu, J.; Deng, J., Chiral Surfactant-Type Catalyst: Enantioselective Reduction of Long-Chain Aliphatic Ketoesters in Water. J. Org. Chem. 2015, 80, 4419–4429.
85. Catalytic amidation reaction of ester and amine using alkoxide catalyst. J.P. patent 2013163657 2013.
86. Neo, A. G.; Delgado, J.; Polo, C.; Marcaccini, S.; Marcos, C. F., A new synthesis of β-keto amides by reduction of Passerini adducts. Tetrahedron Lett. 2005, 46, 23–26.
87. Shimada, N.; Hirata, M.; Koshizuka, M.; Ohse, N.; Kaito, R.; Makino, K., Diboronic Acid Anhydrides as Effective Catalysts for the Hydroxy-Directed Dehydrative Amidation of Carboxylic Acids. Org. Lett. 2019, 21, 4303–4308.
88. Wang, Y.-C.; Yan, T.-H., Al–Hg promoted chemoselective dehalogenation of halohydrin aldol adducts. Chem. Commun. 2000, 545–546.
89. Méndez-Sánchez, D.; Mourelle-Insua, Á.; Gotor-Fernández, V.; Lavandera, I., Synthesis of α-Alkyl-β-Hydroxy Amides through Biocatalytic Dynamic Kinetic Resolution Employing Alcohol Dehydrogenases. Adv. Synth. Catal. 2019, 361, 2706–2712.
90. Kakei, H.; Nemoto, T.; Ohshima, T.; Shibasaki, M., Efficient Synthesis of Chiral α- and β-Hydroxy Amides: Application to the Synthesis of (R)-Fluoxetine. Angew. Chem., Int. Ed. 2004, 43, 317–320.
91. Tsuji, H.; Yamamoto, H., Hydroxy-Directed Amidation of Carboxylic Acid Esters Using a Tantalum Alkoxide Catalyst. J. Am. Chem. Soc. 2016, 138, 14218–14221.
92. Tang, C.-G.; Lin, H.; Zhang, C.; Liu, Z.-Q.; Yang, T.; Wu, Z.-L., Highly enantioselective bioreduction of N-methyl-3-oxo-3-(thiophen-2-yl) propanamide for the production of (S)-duloxetine. Biotechnol. Lett. 2011, 33, 1435–1440.
93. Goldys, A. M.; Núñez, M. G.; Dixon, D. J., Creation through Immobilization: A New Family of High Performance Heterogeneous Bifunctional Iminophosphorane (BIMP) Superbase Organocatalysts. Org. Lett. 2014, 16, 6294–6297.
94. Kobayashi, S.; Xu, P.; Endo, T.; Ueno, M.; Kitanosono, T., Chiral Copper(II)-Catalyzed Enantioselective Boron Conjugate Additions to α,β-Unsaturated Carbonyl Compounds in Water. Angew. Chem., Int. Ed. 2012, 51, 12763–12766.