Asymmetric Synthesis of Densely Functionalized Medium-Ring Carbocycles and Lactones through Modular Assembly and Ring-Closing Metathesis of Sulfoximine-Substituted Trienes and Dienynes
作者:Michal Lejkowski、Prabal Banerjee、Sabine Schüller、Alexander Münch、Jan Runsink、Cornelia Vermeeren、Hans-Joachim Gais
DOI:10.1002/chem.201103060
日期:2012.3.19
(S)‐diastereomer delivered in a cascade of cross metathesis and RCDEM 22‐membered macrocycles. RCDEM of cyclic trienes furnished bicyclic carbocycles with a bicyclo[7.4.0]tridecane and bicyclo[9.4.0]pentadecane skeleton. Selective transformations of the sulfoximine‐ and bissilyloxy‐substituted carbocycles were performed including deprotection, cross‐coupling reaction and reduction of the sulfoximine moiety
已经开发出稠密官能化的7-11元碳环和9-11元内酯的不对称合成。它的关键步骤是用模块组装硫磺亚胺取代的C和O系三烯和C系二烯,以及它们在Ru催化下的闭环二烯和烯炔复分解(RCDEM和RCEYM)。C链状三烯和二烯的合成包括以下步骤:1)对映体纯的钛酸烯丙基亚砜基亚砜与不饱和醛的羟烷基化,2)烯基亚砜基亚砜的α-锂化,3)α的烷基化,羟基烷基化,甲酰化和酰化-硫代链烯基亚砜亚胺,以及4)将格氏试剂添加到α-甲酰基(酰基)烯基亚砜基亚砜。亚砜亚胺基团在步骤1)和4)中提供了高不对称诱导作用。用第二代Ru催化剂对亚砜亚胺取代的三烯进行的RCDEM立体选择性地提供了相应的功能化7-11元碳环。非对映异构的甲硅烷氧基取代的1,6,12-三烯的RCDEM显示出反应性上的有趣差异。而(R)-非对映异构体给出了11元的碳环,(S)非对映异构体以交叉复分解和RCDEM 22元大环化合物的级联传递。环状三烯的RCDEM为双环碳环提供了双环[7