E,Z-Stereodivergent synthesis of N-tosyl α,β-dehydroamino esters via a Mukaiyama–Michael addition
作者:Miguel Espinosa、Andrea García-Ortiz、Gonzalo Blay、Luz Cardona、M. Carmen Muñoz、José R. Pedro
DOI:10.1039/c5ra27354d
日期:——
The stereodivergent synthesis of N-tosyl α,β-dehydroamino estersvia a Mukaiyama–Michael addition is reported. The reaction of silylketene acetals with N-tosylimines derived from β,γ-unsaturated α-keto esters in dichloromethane provided the corresponding (Z)-α,β-dehydroamino esters while the (E)-isomers were obtained when the reaction was carried out in the presence of 10 mol% copper(II) triflate.
Asymmetric Sequential Aza-Diels-Alder and<i>O</i>-Michael Addition: Efficient Construction of Chiral Hydropyrano[2,3<i>-b</i>]pyridines
作者:Xiang Yin、Qingqing Zhou、Lin Dong、Yingchun Chen
DOI:10.1002/cjoc.201200942
日期:2012.11
An asymmetric aza‐Diels‐Alder and O‐Michael addition sequence has been developed to construct chiral hydropyrano[2,3‐b]pyridine derivatives with good yields and excellent stereoselectivity, by starting with N‐Ts‐1‐aza‐1,3‐butadienes and aliphatic aldehydes tethered to an α,β‐unsaturated ketone motif. A tandem O‐Michael addition reaction was completed via acid catalysis.
已经开发了一种不对称的aza-Diels-Alder和O - Michael加成序列,从N -Ts-1-aza-1,3开始,构建了具有良好收率和优异立体选择性的手性氢吡喃并[2,3- b ]吡啶衍生物。-α,β-不饱和酮基拴系的丁二烯和脂族醛。通过酸催化完成了O- Michael串联反应。