Methodology for <i>in Situ</i> Protection of Aldehydes and Ketones Using Trimethylsilyl Trifluoromethanesulfonate and Phosphines: Selective Alkylation and Reduction of Ketones, Esters, Amides, and Nitriles
作者:Kenzo Yahata、Masaki Minami、Yuki Yoshikawa、Kei Watanabe、Hiromichi Fujioka
DOI:10.1248/cpb.c13-00666
日期:——
ensuing reactions of other carbonyl moieties in the substrates liberates the aldehyde moiety, a sequence involving aldehyde protection, transformation of other carbonyl groups, and deprotection can be accomplished in a one-pot manner. Furthermore, the use of PEt(3) instead of PPh(3) enables ketones to be converted in situ to their corresponding O,P-ketal type phosphonium salts and, consequently, selective
已经开发了在醛存在下选择性转化酮,酯,Weinreb酰胺和腈的方法。PPh(3)-三甲基甲硅烷基三氟甲磺酸盐(TMSOTf)的组合使用可促进醛选择性转化为其相应的,临时保护的O,P-乙缩醛型phospho盐。因为随后在底物中其他羰基部分反应之后的水解后处理释放了醛部分,所以涉及醛保护,其他羰基的转化和脱保护的序列可以一锅法完成。此外,使用PEt(3)代替PPh(3)可使酮原位转化为其相应的O,P-缩酮型phospho盐,并因此实现酯,Weinreb酰胺,可以在酮存在下进行腈反应。该方法学适用于各种二羰基化合物,包括具有杂芳族骨架和羟基保护基团的底物。