Cinchona-derived ammonium salts-catalyzed aza Diels–Alder reaction of Danishefsky’s diene with imines
作者:Yohan Park、Eunyoung Park、Hyojun Jung、Yeon-Ju Lee、Sang-sup Jew、Hyeung-geun Park
DOI:10.1016/j.tet.2010.12.002
日期:2011.2
Described is the efficiency of cinchona-derived quaternary ammonium salts as Lewis acid organocatalysts in aza Diels–Alder reaction of Danishefsky’s diene 1 with imines 2 and 16, providing 1,2-dialkyl-2,3-dihydro-4-pyridinones 3 and cyclic dihydropyridones 17, respectively. Among the nine of cinchonidine-derived quaternary ammonium catalysts prepared, N-2′,3′,4′-trifluorobenzyl-O-benzylcinchonidinum
描述了金鸡纳衍生的季铵盐在aza Diels-Danishefsky二烯1与亚胺2和16的Alder反应中作为路易斯酸有机催化剂的效率,提供1,2-二烷基-2,3-二氢-4-吡啶酮3和环状二氢吡啶酮17。在所制备的九种由辛可尼定衍生的季铵催化剂中,N -2',3',4'-三氟苄基-O-苄基钦可宁溴化物(6)具有最高的化学收率(高达99%)。对结构-催化效率关系的系统研究表明,2',3',4'-三氟苄基,奎尼丁和喹啉部分是必不可少的。