Asymmetric Preparation of New N,N-Dialkyl-2-amino-1,1,2-triphenylethanol Catalysts and a Kinetic Resolution in the Addition of Diethylzinc to Flavene-3-carbaldehydes
摘要:
Enantiopure N,N-dialkyl-(S)-2-amino-1,1,2-triphenylethanols were prepared using a new synthetic methodology and tested for their ability to catalyze the enantioselective addition of diethylzinc to aldehydes. The structural modification of N- substituents of the catalysts led us to identify N- methyl- N-(S)-1-phenylethyl-substituted 4d as an effective catalyst for the addition. Also disclosed is a kinetic resolution of racemic flavene-3-carbaldehydes with the chiral catalyst.
strategy has been developed for the synthesis of chromeno[3,4-b]pyrrol-4(3H)-one and substituted pyrrole derivatives through 1,5-electrocyclization of conjugated azomethine ylides. This is the first example of the preparation of highly substituted pyrrole derivatives from chromene-3-carboxaldehydes (non-enolizable aldehydes) and N-alkyl amino acids/esters. This method is simple and applicable to a diverse
已开发出一种新的策略,用于通过共轭偶氮甲亚胺的1,5-电环化合成chromeno [3,4- b ] pyrrol-4(3 H)-one和取代的吡咯衍生物。这是由亚甲基-3-羧醛(不可烯化的醛)和N-烷基氨基酸/酯制备高度取代的吡咯衍生物的第一个例子。该方法很简单,适用于各种基材。