Tandem Iminium/Copper Catalysis: Highly Enantioselective Synthesis of α,β-Disubstituted Aldehydes
作者:Ju-Hye Kim、Eun-Jin Park、Hwa-Jung Lee、Xuan-Huong Ho、Hyo-Sang Yoon、Pilsoo Kim、Hoseop Yun、Hye-Young Jang
DOI:10.1002/ejoc.201300333
日期:2013.7
iminium/copper catalysis allowed highly optically active α,β-disubstituted aldehydes to be synthesized with good yields in one-pot fashion. The β-substitution took place through iminium-catalyzed Michael addition of nitromethane or diethyl malonate to the α,β-unsaturated aldehydes, followed by copper-assisted addition of TEMPO (2,2,6,6-tetramethylpiperidin-1-yloxyl) at the aldehyde α-position. An
为了在环境友好和经济的条件下合成具有生物和合成价值的产品,不对称有机催化反应与铜催化反应相结合。这种亚胺/铜催化允许以一锅法以良好的收率合成高光学活性的 α,β-二取代醛。β-取代是通过亚胺催化硝基甲烷或丙二酸二乙酯与 α,β-不饱和醛的迈克尔加成,然后在铜辅助下加入 TEMPO(2,2,6,6-四甲基哌啶-1-yloxyl)醛的α位。亚胺/铜催化的串联加成产物转化为 3,4,5-三取代哌啶,用于 X 射线晶体学分析。
N719 Dye-Sensitized Organophotocatalysis: Enantioselective Tandem Michael Addition/Oxyamination of Aldehydes
作者:Hyo-Sang Yoon、Xuan-Huong Ho、Jiyeon Jang、Hwa-Jung Lee、Seung-Joo Kim、Hye-Young Jang
DOI:10.1021/ol3011858
日期:2012.7.6
A remarkably efficient photosensitizer, N719 dye, was used in asymmetric tandem Michael addition/oxyamination of aldehydes, rendering alpha,beta-substituted aldehydes in good yields with excellent levels of enantioselectivity and diastereoselectivity. This is the first report of a multiorganocatalytic reaction involving iminium catalysis and photoinduced singly occupied molecular orbital (SOMO) catalysis. This reaction is expected to expand the scope of tandem organocatalytic reactions.