Regioselective alkylation of 2-trimethylsiloxyfuran; direct access to 4-substituted but-2-en-4-olides
作者:Charles W. Jefford、Adam W. Sledeski、John Boukouvalas
DOI:10.1039/c39880000364
日期:——
Primary iodides alkylate 2-trimethylsiloxyfuran in the presence of a molar excess of silver trifluoroacetate to give the 4-alkylbut-2-en-4-olides in 55–81% yield; as an illustration of the method, the cytotoxic marine sponge constituent, 4-(methoxycarbonylmethyl)but-2-en-4-olide was prepared in 79% yield in one step.
Reported herein is a visible‐light‐mediated radical approach to the α‐alkylation of ketones. This method exploits the ability of a nucleophilic organocatalyst to generate radicals upon SN2‐based activation of alkyl halides and blue light irradiation. The resulting open‐shell intermediates are then intercepted by weakly nucleophilic silyl enol ethers, which would be unable to directly attack the alkyl