Enantioselective, Palladium-Catalyzed α-Arylation of <i>N</i>-Boc Pyrrolidine: <i>In Situ</i> React IR Spectroscopic Monitoring, Scope, and Synthetic Applications
作者:Graeme Barker、Julia L. McGrath、Artis Klapars、Darren Stead、George Zhou、Kevin R. Campos、Peter O’Brien
DOI:10.1021/jo2011347
日期:2011.8.5
the process; use of (−)-sparteine and the (+)-sparteine surrogate to access products with opposite configuration; development of a catalytic asymmetric lithiation–Negishi coupling reaction; extension to a wide range of heteroaromatic bromides; total synthesis of (R)-crispine A, (S)-nicotine and (S)-SIB-1508Y via short synthetic routes; and examples of α-vinylation of N-Boc pyrrolidine using vinyl bromides
已对N - Boc吡咯烷的对映选择性Pd催化的α-芳基化进行了全面研究。该方案包括在-78°C的条件下在TBME或Et 2 O中使用s -BuLi /(-)-天冬氨酸对N -Boc吡咯烷进行质子化,ZnCl 2的金属转移和使用Pd(OAc)2,t -Bu 3 P的Negishi偶联-HBF 4和芳基溴化物。本文报告了一些新功能,包括原位反应红外光谱监测过程;使用(-)-partaine和(+)-sparteine代理访问具有相反配置的产品;催化不对称锂化-Negishi偶联反应的发展;扩展到广泛的杂芳族溴化物;(R)-crispine A,(S)-尼古丁和(S)-SIB-1508Y通过短合成路线的全合成;以及使用乙烯基溴的N -Boc吡咯烷的α-乙烯基化的例子,其示例为天然存在的(+)-maackiamine的全合成(因此将其构型确定为(R))。以这种方式,描述了该方法的全部范围和局限性。