Acid-Free, Aminoborane-Mediated Ugi-Type Reaction Leading to General Utilization of Secondary Amines
作者:Yusuke Tanaka、Tomoaki Hasui、Michinori Suginome
DOI:10.1021/ol701570c
日期:2007.10.1
in the Ugi reaction by using aminoborane 1 as an iminiumiongenerator. Aldehydes, secondary amines, and isocyanides are coupled in the presence of 1 at room temperature, giving the corresponding alpha-amino amides in good yields. The nonacidicreaction conditions are beneficial for unique chemoselectivity, where the aldimine functionality is left intact in the present Ugi-typereaction.
Mannich-type reactions of aldehydes with secondary amines and a ketene silyl acetal were promoted by trimethoxyborane in DMSO to afford the corresponding β-amino esters in good yields. B(OMe)3 also promoted Ugi-typereactions ofaldehydes with secondary amines and isocyanides in 1,2-dichloroethane, which leads to the formation of α-amino amides. In these reactions, trimethoxyborane serves as an inexpensive
Diarylborinic Acid Derivatives as a Catalytic Iminium Ion Generator in the Mannich-Type Reaction Using Secondary Amines, Aldehydes, and Ketene Silyl Acetals
作者:Michinori Suginome、Yusuke Tanaka、Tomoaki Hasui
DOI:10.1055/s-2008-1072724
日期:2008.5
Reactions of secondary amines, aldehydes, and ketene silyl acetals were efficiently promoted by catalytic amounts of diarylborinic acid esters, Ar 2 B(OR), affording β-amino esters selectively with no formation of the corresponding β-hydroxy esters.
催化量的二芳基硼酸酯 Ar 2 B(OR) 有效地促进了仲胺、醛和乙烯酮甲硅烷基缩醛的反应,选择性地提供了 β-氨基酯,而不会形成相应的 β-羟基酯。