Palladium-Catalyzed β-C(sp3)-H Arylation of Silyl Prop-1-en-1-ol Ethers with Aryl Halides: Entry to α,β-Unsaturated Ketones

摘要

A palladium(0)-catalyzed beta-C(sp(3))-H arylation of silyl prop-1-en-1-ol ethers with aryl halides for the synthesis of alpha,beta-unsaturated ketones is presented. In contrast to the reported beta-C(sp(3))-H arylation of ketones, the chemoselectivity of this current method relies on the Pd(0) catalytic systems and reaction temperatures: While using the Pd(dba)(2)/DavePhos/KF system at 80 degrees C resulted in beta-C(sp(3))-H monoarylation to produce beta-monoarylated alpha,beta-unsaturated ketones, harnessing the Pd(OAc)(2)/t-Bu XPhos/K2HPO4 system at 110 degrees C induced beta-C(sp(3))-H diarylation to afford beta,beta-diarylated alpha,beta-unsaturated ketones. The method provides a versatile route that uses readily available ketone-derivatized alpha-nonsubstituted silyl prop-1-en-1-ol ethers as the alkene sources and is characterized by a good functional group compatibility, a broad substrate scope, and an excellent selectivity.

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