Catalytic asymmetric conjugate addition of various α-mercaptoketones to α,β-unsaturated N-acylated oxazolidin-2-ones with bifunctional organocatalyst
作者:Bo-Liang Zhao、Da-Ming Du
DOI:10.1039/c4ra02400a
日期:——
catalysed enantioselectiveconjugateMichaeladdition reaction of various α-mercaptoketones to α,β-unsaturatedN-acylated oxazolidinones under mild reaction conditions has been developed. This catalytic reaction afforded the corresponding adducts in good yields with high enantioselectivities (up to 92% ee). This is the first example of organocatalysed sulfa-Michael addition using various α-mercaptoketones
Highly Efficient Asymmetric Michael Addition of Diaryl Phosphine Oxides to α,β-Unsaturated N-Acylated Oxazolidin-2-ones
作者:Depeng Zhao、Linqing Wang、Dongxu Yang、Yixin Zhang、Rui Wang
DOI:10.1002/asia.201200025
日期:2012.5
A highlyefficientasymmetricMichael reaction of diarylphosphineoxides with α,β‐unsaturated N‐acylated oxazolidinones has been developed. Excellent enantioselectivities (up to >99 % ee) and chemical yields (up to 99 %) were achieved with a broad substrate scope of the oxazolidinones. The bidentate property of oxazolidinones was found to be critical for high enantioselectivities.
An Access to Chiral Phthalides: Enantioselective Synthesis of Escitalopram
作者:Rosaria Schettini、Antonella Dentoni Litta、Arianna Sinibaldi、Assunta D'Amato、Alicja M. Araszczuk、Marina Sicignano、Letizia Pagliarulo、Simone Naddeo、Giovanni Pierri、Francesco De Riccardis、Irene Izzo、Giorgio Della Sala
DOI:10.1002/adsc.202400007
日期:2024.4.9
A method for the asymmetric synthesis of phthalides containing a stereogenic γ-carbon has been described. The protocol, based on the arylogous Michael addition to chiral alkenoyl oxazolidinones catalyzed by a crown ether under phase-transfer conditions does not require anhydrous conditions and uses commercially available materials. A complete syn-stereocontrol is achieved and facial diastereoselectivities
Asymmetric β-Boration of α,β-Unsaturated <i>N</i>-Acyloxazolidinones by [2.2]Paracyclophane-Based Bifunctional Catalyst
作者:Lei Zhao、Yudao Ma、Wenzeng Duan、Fuyan He、Jianqiang Chen、Chun Song
DOI:10.1021/ol302839d
日期:2012.11.16
An efficient copper-catalyzed asymmetric conjugate boration has been achieved by exploiting a new planar and central chiral bicyclic triazolium ligand. This protocol was highly efficient and gave a variety of chiral secondary alkylboronates in 97-99% ee. A preliminary mechanistic study supports the bifunctional nature of the catalyst.