化学
芳基
比纳普
配体(生物化学)
仙磷
磷化氢
催化作用
组合化学
卤代芳基
药物化学
基质(水族馆)
选择性
异丙胺
产量(工程)
有机化学
钯
对映选择合成
冶金
材料科学
受体
地质学
烷基
海洋学
生物化学
作者
Joseph M. Fox,Xiaohua Huang,A. Chieffi,Stephen L. Buchwald
摘要
Bulky, electron-rich phosphine ligands with a biphenyl backbone, when combined with Pd(OAc)2, give highly active catalysts for the α-arylation of ketones. The ligand 2-methyl-2'-dicyclohexylphosphinobiphenyl is particularly effective, and with 0.1−1.0 mol % Pd, a large variety of aryl halides and ketones react efficiently and with high selectivity. For two types of substrates, the ligands BINAP and Xantphos are more effective than the biphenyl-based ligands. It is also shown that K3PO4 can be used as the base in these reactions, and that base-sensitive functional groups are better tolerated if this is used instead of NaOtBu or NaHMDS. In some cases, α-aryl ketones can be produced without adding a ligand to the reaction. Although the substrate scope of the ligandless conditions is limited, some combinations react in high yield, and in one case, 100 000 turnovers were obtained. The results of experiments on the Pd-catalyzed arylation of diethyl malonate, cyclic 1,3-diketones, and nitroalkanes are also reported.
科研通智能强力驱动
Strongly Powered by AbleSci AI