Titanium Reagents for the Synthesis of 2-Substituted Benzo[<i>b</i>]thiophenes on the Solid Phase
作者:Christine F. Roberts、Richard C. Hartley
DOI:10.1021/jo049344o
日期:2004.9.1
Titanium(IV) benzylidenes (Schrock carbenes) bearing a masked sulfur nucleophile in the ortho position were generated from thioacetals with use of low-valent titanocene complex Cp2Ti[P(OEt)3]2 and alkylidenated Merrifield resin-bound esters to give enol ethers. Treatment of the resin-bound enol ethers with a 5:5:90 mixture of TFA, TFAA, and dichloromethane led to cleavage from resin, removal of the
使用低价二茂钛配合物Cp 2 Ti [P(OEt)3 ] 2和烷基化的Merrifield树脂结合的酯从硫缩醛中生成在邻位带有掩蔽的硫亲核试剂的钛(IV)苄叉基(Schrock carbenes)烯醇醚。用TFA,TFAA和二氯甲烷的5:5:90混合物处理与树脂结合的烯醇醚,导致从树脂上裂解,除去叔丁基二甲基甲硅烷基(TBDMS)保护基,并伴随环化反应完成无痕固体苯并噻吩的相合成(SPS)。将连接基的性质从酸稳定的转变为酸敏感的,确保了良好的纯度。