作者:P. Veeraraghavan Ramachandran、Pravin D. Gagare、Kaumba Sakavuyi、Paul Clark
DOI:10.1016/j.tetlet.2010.04.014
日期:2010.6
A variety of primary, secondary, and tertiary amines were prepared in 84–95% yields using ammonia borane for the reductiveamination of aldehydes and ketones in the presence of titanium isopropoxide.
Borane-amines undergo exclusive monoacetoxylation to trifluoroacetoxyborane-amines (TFAB-amines), which serve as chemoselective reagents for direct reductiveamination of aldehydes and ketones. TFAB-NEt3 has been established as mild and highly selective compared to widely-used NaBH3CN and Na(AcO)3BH, even at higher temperatures with challenging substrates. A mechanism involving polyaminoborane formed