- Synthesis of 1-acylamino-1-(trimethylsiloxy)alkanes by trimethylsilyl trifluoromethanesulfonate-catalysed addition of bis(trimethylsilyl)amides to aldehydes
-
Bis(trimethylsilyl)formamide reacts with aldehydes in refluxing chloroform, or at room temperature with catalysis by trimethylsilyl trifluoromethanesulfonate, to give 1-acylamino-1-(trimethylsiloxy)alkanes; similar results are obtained with other bis(trimethylsilyl)amides, but surprisingly not with bis(trimethylsilyl)acetamide, and addition of bis(trimethylsilyl)formamide to ketones and acetals can also be accomplished using TMS triflate as catalyst.
- Johnson, A. Peter,Luke, Richard W. A.,Steele, Robert W.,Boa, Andrew N.
-
-
Read Online
- A NHC-silyliumylidene cation for catalytic N?formylation of amines using carbon dioxide
-
This study describes the use of a silicon(II) complex, namely, the NHC-silyliumylidene cation complex [(IMe)2SiH]I (1, IMe =:C{N(Me)C(Me)}2), to catalyze the chemoselective N-formylation of primary and secondary amines using CO2 and PhSiH3 under mild conditions to afford the corresponding formamides as a sole product (average reaction time: 4.5 h; primary amines, average yield: 95%, average TOF: 8 h?1; secondary amines, average yield: 98%, average TOF: 17 h?1). The activity of 1 and product yields outperform the currently available non-transition-metal catalysts used for this catalysis. Mechanistic studies show that the silicon(II) center in complex 1 catalyzes the C?N bond formation via a different pathway in comparison with non-transition-metal catalysts. It sequentially activates CO2, PhSiH3, and amines, which proceeds via a dihydrogen elimination mechanism, to form formamides, siloxanes, and dihydrogen gas.
- Leong, Bi-Xiang,Teo, Yeow-Chuan,Condamines, Cloe,Yang, Ming-Chung,Su, Ming-Der,So, Cheuk-Wai
-
p. 14824 - 14833
(2020/12/21)
-
- Method for the preparation of persilylated carboxylic acid amides
-
Disclosed is a method of preparing bis-trimethylsilylamides of carboxylic acids from the carboxylic acid amide by mixing two equivalents of trimethylchlorosilane and an excess of hexamethyldisilazane, heating the mixture to 40° to 80° C. and adding two equivalents of a tertiary amine as acid acceptor. The method results in substantially improved purity and yield of end product.
- -
-
-