手性C 2 -对称 3,3'-二氨基甲基-联萘酚 ( AMB ) 是一种用于三取代丙烯腈不对称环氧化的有机催化剂。使用氢过氧化枯烯 (CHP) 作为氧化剂,3,3'-双(( R , R )-2-苯乙基氨基甲基)-( R )-联萘酚( AMB2 )在 - 30 °C 得到手性环氧化物作为单一非对映异构体,对映选择性范围为 15% ee 至 97% ee。
A remote β,γ-regioselective asymmetric inverse-electron-demand oxa-Diels–Alder reaction between allylic ketones and α-cyano-α,β-unsaturated ketones has been developed through induced extended dienamine catalysis of a cinchona-derived primary amine. A spectrum of densely substituted dihydropyran frameworks were efficiently produced with excellent enantioselectivity and fair to exclusive diastereoselectivity
Organocatalytic Asymmetric Synthesis of Pentasubstituted Tetrahydrothiopyrans Bearing a Quaternary Centre through a Double Michael Reaction
作者:Subhas Pan、Buddhadeb Mondal
DOI:10.1055/s-0036-1591736
日期:2018.3
An organocatalytic, asymmetric, double-Michael strategy has been developed employing trans-α-cyano-α,β-unsaturated ketones for the synthesis of pentasubstituted tetrahydrothiopyrans bearing a quaternary center. A proline-derived bifunctional thiourea was found to be the most effective catalyst for this reaction. With 10 mol% of catalyst, good yields and good to high diastereomeric ratios, as well as
Asymmetric Synthesis of Trisubstituted Tetrahydrothiophenes Bearing a Quaternary Stereocenter via Double Michael Reaction Involving Dynamic Kinetic Resolution
The stereoselective synthesis of highly functionalized tetrahydrothiophenes bearing threecontiguousstereocenters, one of them quaternary, can be achieved by reacting trans-α-cyano-α,β-unsaturated ketones and trans-tert-butyl 4-mercapto-2-butenoate in the presence of a readily available amine thiourea. The products are obtained in high yield, good diastereoselectivity, and excellent enantioselectivity
While phosphine-mediated reactions have been extensively explored over the past few decades, the catalytic cyclopropanation reaction via a phosphonium ylide pathway has been significantly underdeveloped, and an intermolecular version still remains to be disclosed. Presented herein is a catalytic cyclopropanation reaction between readily available benzylbromides and activated alkenes, such as α-cyano
Acylcyanation of Terminal Acetylenes: Palladium-Catalyzed Addition of Aryloyl Cyanides to Arylacetylenes
作者:Kyoko Nozaki、Naomasa Sato、Hidemasa Takaya
DOI:10.1021/jo00089a006
日期:1994.5
Two different electron-withdrawing carbon substituents (aryloyl group and nitrile group) were introduced into terminal arylacetylenes by a new method, palladium-catalyzed intermolecular acylcyanation of the acetylenic bonds.