Tetrahedron

Isotope effects and the distinction between synchronous, asynchronous, and stepwise Diels–Alder reactions

DA Singleton, BE Schulmeier, C Hang, AA Thomas…

Index: Singleton, Daniel A.; Schulmeier, Brian E.; Hang, Chao; Thomas, Allen A.; Leung, Shun-Wang; Merrigan, Steven R. Tetrahedron, 2001 , vol. 57, # 24 p. 5149 - 5160

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Citation Number: 57

Abstract

A variety of symmetrical or nearly symmetrical Diels–Alder reactions are studied by a combination of experimental isotope effects, theoretical calculations, and rate observations. Becke3LYP calculations predicted highly asynchronous transition structures for Diels–Alder reactions of bis (boryl) acetylenes, dialkyl acetylenedicarboxylates, triazolinediones, and dialkyl maleates. Rate observations and kinetic isotope effects are consistent with these ...