Giving a Second Chance to Ir/Sulfoximine-Based Catalysts for the Asymmetric Hydrogenation of Olefins Containing Poorly Coordinative Groups
作者:Maria Biosca、Oscar Pàmies、Montserrat Diéguez
DOI:10.1021/acs.joc.9b00829
日期:2019.6.21
This work identifies a family of Ir/phosphite-sulfoximine catalysts that has been successfully used in the asymmetrichydrogenation of olefins with poorly coordinative or noncoordinative groups. In comparison with analogue Ir/phosphine-sulfoximine catalysts previously reported, the presence of a phosphite group extended the range of olefins than can be efficiently hydrogenated. High enantioselectivities
Asymmetric Catalytic Enantio- and Diastereoselective Boron Conjugate Addition Reactions of α-Functionalized α,β-Unsaturated Carbonyl Substrates
作者:Jian-Bo Xie、Siqi Lin、Shuo Qiao、Guigen Li
DOI:10.1021/acs.orglett.6b01998
日期:2016.8.5
established for the asymmetric boron conjugate addition of B2pin2 onto α-functionalized (involving C, N, O, and Cl) α,β-unsaturated carbonyls under mild, neutral conditions involving Cu[(S)-(R)-ppfa]Cl, AgNTf2, and alcohols. The dual additives of AgNTf2 and alcohols were found to play crucial roles for achieving high catalytic activity and enantio- and diastereoselectivity (up to 98% ee and 70:1 dr).
An efficient cobalt-catalyzed asymmetrichydrogenation of internal simple enamides has been developed, especially its convergent pattern for E/Z-substrates. Excellent enantioselectivity, wide substrate scope, and valuable applications were shown.
Asymmetric and Chemoselective Iridium Catalyzed Hydrogenation of Conjugated Unsaturated Oxime Ethers
作者:Shaohu Zhao、Bram B. C. Peters、Haili Zhang、Ruize Xue、Yixin Yang、Liuying Wu、Tianrui Huang、Lei He、Pher G. Andersson、Taigang Zhou
DOI:10.1002/chem.202401333
日期:2024.7.11
The selective hydrogenation of α,β-unsaturated oxime ethers is described. The hydrogenation reaction proceeded smoothly at (20–50 bar) room temperature. The generated chiral oxime ethers showed good isolated yields and excellent enantioselectivity (84 %–99 % yield, >97 % ee). The hydrogenation products could be further hydrolysed to chiral ketones.
Iridium phosphinitoxazoline complexes were found to be new efficient catalysts for the asymmetric hydrogenation of arylated alpha,beta-unsaturated ketones. Linear as well as cyclic substrates are hydrogenated with similar success, giving selectivities of up to 99.7% ee.