Stereospecific, Ligand-Free Synthesis of All-Carbon Quaternary Stereocenters from Tertiary Benzylic Carboxylates

Abstract

Nickel-catalyzed, stereospecific cross-couplings via activation of secondary C–O bonds has been well developed in the past few years. Meanwhile, stereospecific cross-couplings of tertiary electrophiles have been rarely explored. Herein, we describe a nickel-catalyzed, ligand-free Suzuki-Miyaura vinylation, using easily prepared, highly enantioenriched tertiary benzylic carboxylates to install all-carbon quaternary stereocenters in high yields and ee’s. In addition to allowing stereospecific vinylation of these substrates for the first time, this method overcomes the longstanding requirement for a naphthyl group on the benzylic carboxylate<br>

Development of Nickel-Catalyzed Cross-Coupling of Alcohol Derivatives to Construct Carbon-Carbon Bonds

“…最近 Watson 课题组 [84] 又实现了镍催化无配体参与 的 Suzuki-Miyaura 乙烯基化反应, 以高对映体富集的叔 苄基羧酸盐衍生物为原料, 高收率和高对映选择性地构 筑了一个季碳手性中心. 该方法第一次克服了在此类反 应中对苄基羧酸盐上的萘基的长期需求, 可以使用简单 芳基底物就能实现反应(Scheme 52).…”