Stereoselective Addition of the Titanium Enolate of <i>N</i>-Acetyl (4<i>S</i>)-Isopropyl-1,3-thiazolidine-2-thione to Five-Membered <i>N</i>-Acyl Iminium Ions
作者:Efraín Barragán、Horacio F. Olivo、Moisés Romero-Ortega、Seth Sarduy
DOI:10.1021/jo050188a
日期:2005.5.1
Addition of the chlorotitanium enolate of N-acetyl 4-isopropyl-1,3-thiazolidine-2-thione to five-membered, N-Substituted N-acyl iminium ions furnished the corresponding Mannich-type addition products with good diastereoselectivity and in good yields. The synthetic utility of the addition product 8 was demonstrated in a chemospecific anti-aldol reaction with cinnamaldehyde. By using this strategy, we
N-乙酰基4-异丙基-1,3-噻唑烷-2-硫酮的氯钛烯醇盐向五元N-取代的N-酰基亚胺离子的加成为相应的曼尼希型加成产物提供了良好的非对映选择性和高收率。在与肉桂醛的化学特异性抗醛醇缩合反应中证明了加成产物8的合成效用。通过使用这种策略,我们使用相同的手性助剂构建了三个具有高度立体控制的连续手性中心。加成产物2和醛醇缩合产物14的X射线晶体学分析表明它们的绝对立体化学。