科研之友
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摘要
An efficient system for the direct catalytic intermolecular -arylation of acetamide derivatives with aryl bromides and chlorides is presented. The palladium catalyst is supported by Kwong's indole-based phosphine ligand and provides monoarylated amides in up to 95% yield. Excellent chemoselectivities (>10:1) in the mono- and diarylation with aryl bromides were achieved by careful selection of bases, solvents, and stoichiometry. Under the coupling conditions, the weakly acidic -protons of amides (pK(a) up to 35) were reversibly depotonated by lithium tert-butoxide (LiO-t-Bu), sodium tert-butoxide (NaO-t-Bu) or sodium bis(trimethylsilyl)amide [NaN(SiMe3)(2)].
- 出版日期2014-1-13
- 单位中国农业大学
