Metallocupration of acetylenic silyl ketone: synthesis and reactivity of polymetalated functionalized building blocks

Treatment of ethynyl triphenylsilyl ketone (1) with stannylcuprates affords the corresponding bismetalated compounds. In particular, the use of tributylstannylcuprate as the Michael donor, allows fine tuning of the reactional polarity of the carbon at position 3 of the enonic framework. The intermediate cuprate can be further reacted in situ to afford an easy entry into the class of polyfunctionalized compounds such as exomethylenic 1,3-diketones 12, useful building blocks for natural product synthesis