Bi(OTf)₃-Catalyzed Alkyl-Intercepted Meyer–Schuster Rearrangement of Propargylic Alcohols for the Synthesis of 1,2,3,5-Tetrasubstituted Pentane-1,5-diones

Abstract

An alkyl intercepted Meyer–Schuster rearrangement reaction with α,β-unsaturated ketones as the electrophiles was first investigated, which provided a facile method to construct 2-methylene-pentane-1,5-diones. Then the in situ generated 2-methylene-pentane-1,5-diones underwent a Michael addition to give diverse 2-malononitrile methyl substituted pentane-1,5-diones in a one-pot fashion. This transformation was reliable on a gram scale. The high yield, convenient experimental operation, and 100% atom economy made it a valuable method for the construction of 1,2,3,5-tetrasubstituted pentane-1,5-dione derivatives.

Synthesis of 2-acyl benzofurans and indoles based on nucleophile-intercepted Meyer–Schuster rearrangement of o-hydroxyphenyl and o-aminophenyl propargylic alcohols

“…2), broadening the synthetic utility of this “classic reaction”. 8 This M–S rearrangement intercepted by electrophiles was classified as electrophile-intercepted M–S rearrangement (EIMSR). In contrast to these EIMSR approaches, nucleophilic interception to trap the umpolung C2 centre of allenyl intermediates (such as 9 ) would bring in new insights into Meyer–Schuster chemistry.…”