General, Robust, and Stereocomplementary Preparation of α,β-Disubstituted α,β-Unsaturated Esters
作者:Hidefumi Nakatsuji、Hiroshi Nishikado、Kanako Ueno、Yoo Tanabe
DOI:10.1021/ol9013359
日期:2009.10.1
for α,β-disubstituted α,β-unsaturated esters is performed via three general and robust reaction sequences: (i) Ti−Claisen condensation (formylation) of esters to give α-formyl esters (12 examples, 60−99%), (ii) (E)- and (Z)-stereocomplementary enol p-toluenesulfonylation (tosylation) using TsCl−N-methylimidazole (NMI)−Et3N and LiOH (24 examples, 82−99%), and (iii) stereoretentive Suzuki−Miyaura cross-coupling
α,β-二取代的α,β-不饱和酯的(E)-和(Z)-立体互补制备方法是通过三个常规且稳健的反应顺序进行的:(i)酯的Ti-Claisen缩合(甲酰化)得到α -甲酰基酯(12个例子,60-99%),(ii)(E)-和(Z)-立体互补烯醇对甲苯磺酰化(甲苯磺酸化),使用TsCl- N-甲基咪唑(NMI)-Et 3 N和LiOH(24实例82-99%)和(iii)立体保持Suzuki-Miyaura交叉耦合(18实例64-96%)。