Catalytic, Asymmetric Vinylogous Mukaiyama Aldol Reactions of Pyrrole‐ and Furan‐Based Dienoxy Silanes: How the Diene Heteroatom Impacts Stereocontrol
作者:Claudio Curti、Beatrice Ranieri、Lucia Battistini、Gloria Rassu、Vincenzo Zambrano、Giorgio Pelosi、Giovanni Casiraghi、Franca Zanardi
DOI:10.1002/adsc.201000189
日期:2010.10.9
Denmark’s chiral bisphosphoramide/silicon tetrachloride system performs as an excellent Lewis base-Lewis acid catalyst for the vinylogous Mukaiyama aldol reaction of pyrrole- and furan-based dienoxy silanes with aromatic and heteroaromatic aldehydes. This asymmetric methodology provides a powerful synthetic entry to a variety of δ-hydroxylated γ-butenolide-type frameworks with high efficiency and valuable
丹麦的手性双磷酰胺/四氯化硅系统是出色的路易斯碱-路易斯酸催化剂,可用于吡咯和呋喃基二烯氧基硅烷与芳族和杂芳族醛的乙烯基类Mukaiyama醛醇缩合反应。这种不对称方法为高效合成δ-羟基化γ-丁烯内酯型构架提供了有力的途径,并具有很高的区域,非对映和对映选择性裕度。值得注意的是,乙烯基二烯氧基硅烷供体中杂原子的性质严重影响了非对映异构控制,从带有吸电子N保护基(Boc,Ts和Cbz)的吡咯中生成的顺式构型的羟醛加成物和反式的加成物普遍存在。呋喃或涉及N-烷基/烯基吡咯供体。