Silylium ion mediated 2+2 cycloaddition leads to 4+2 Diels-Alder reaction products.

ABSTRACT: The mechanism of silver(I) and copper(I) catalyzed cycloaddition between 1,2-diazines and siloxy alkynes remains controversial. Here we explore the mechanism of this reaction with density functional theory. Our calculations show that the reaction takes place through a metal (Ag⁺, Cu⁺) catalyzed [2+2] cycloaddition pathway and the migration of a silylium ion [triisopropylsilyl ion (TIPS⁺)] further controls the reconstruction of four-member ring to give the final product. The lower barrier of this silylium ion mediated [2+2] cycloaddition mechanism (SMC) indicates that well-controlled [2+2] cycloaddition can obtain some poorly-accessible IEDDA (inverse-electron demand Diels-Alder reaction) products. Strong interaction of d¹⁰ metals (Ag⁺,

SUBMITTER: Wang HD 

PROVIDER: S-EPMC9814679 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature