铂催化氧杂二环烯烃与芳基磺酰肼的顺式-立体控制开环反应

Platinum-Catalyzed syn-Stereocontrolled Ring-Opening of Oxabicyclic Alkenes with Arylsulfonyl Hydrazides

开发了一种铂催化氧杂二环烯烃与芳基磺酰肼的顺式-立体控制开环反应.该方法显示出高效性和良好的官能团耐受性,在温和条件下能以高达89%的产率得到顺式-2-芳基-1,2-二氢萘-1-醇(3)或脱水产物2-芳基萘(4).此外,通过X射线单晶衍射分析确认了产物(1S*,2R*)-6,7-二溴-2-(4-甲基苯基)-1,2-二氢萘-1-醇(3db)的顺式-1,2-构型.根据实验结果,提出了一种合理的开环反应机理.值得注意的是,在开环反应中,芳基磺酰肼通过释放N2和SO2形成碳负离子作为亲核试剂.

A platinum-catalyzed syn-stereocontrolled ring-opening reaction of oxabicyclic alkenes with arylsulfonyl hydrazides was developed.This protocol exhibited high efficiency and good functional group tolerance,affording cis-2-aryl-1,2-dihydronaphthalen-1-ols(3)or 2-aryl-naphthalenes(4)as dehydrated products in good to excellent yields under mild conditions(up to 89%).In addition,the cis-1,2-configuration of product(1 S*,2 R*)-6,7-dibromo-2-(p-tolyl)-1,2-dihydronaphthalen-1-ol(3 db)was confirmed by X-ray single crystal diffraction analysis.Based on the results,a plausible mechanism for the ring-opening reaction was proposed.Remarkably,arylsulfonyl hydrazides were used as carboanion nucleophiles in the ring-opening reaction via releasing N2 and SO2 in situ.