Mechanistic Studies on α-Trifluoromethylation of Ketones via Silyl Enol Ethers and Its Application to Other Carbonyl Compounds
作者:Kazuyuki Sato、Takashi Yuki、Ryoji Yamaguchi、Tetsuya Hamano、Atsushi Tarui、Masaaki Omote、Itsumaro Kumadaki、Akira Ando
DOI:10.1021/jo9004348
日期:2009.5.15
Synthesis of α-CF3 carbonyl compounds has been recognized to be difficult up to now because the polarization of CF3δ−-Iδ+ is opposite to that of CH3δ+-Iδ−, and this makes it difficult to introduce CF3+ unit to enolates. We recently reported an effective α-trifluoromethylation of ketones by using Et2Zn with Rh catalyst, but the mechanism has not fully been cleared. Now, we carried out the detailed mechanistic
α-CF的合成3的羰基化合物已经被认为是困难的到现在为止,因为CF的极化3 δ- -I δ+是相反的CH 3 δ+ -I δ-,并且这使得难以引入CF 3 +单元烯化。我们最近报道了使用Rh催化剂使用Et 2 Zn可以有效地使酮类产生α-三氟甲基化,但机理尚未完全阐明。现在,我们进行了详细的机理研究,并发现了由Et 2 Zn和RhCl(PPh 3)3衍生的高反应性烷基铑络合物的参与。在这种α-三氟甲基化反应中。此外,该α-三氟甲基化以良好的产率应用于其他类型的羰基化合物。