| |
[摘要]：(A) Node et al. reported a facile and efficient synthesis of allene-1,3-dicarboxylates. The reaction of acetone-l, 3-dicarboxylates with DMC and triethylamine was performed in dichloromethane at room temperature using intermediates of vinyl chloride to afford the corresponding allenes in good to excellent yields. ( B) Isobe and co-workers developed a new method for the synthesis of guanidines by DMC-induced cyclizations of protected thiourea intermediates derived from the corresponding chiral ethylene-diamines. The simple synthetic approach to 1,3-unsubstituted and 1-substituted 2-iminoimidazolidines was explored for new chiral superbases.(7,8) ( C) Isobe et al. demonstrated an alternative cyclization of modified guanidines by using appropriate 2-amino alcohols. The key step of this strategy was the substitution of the hydroxyl group through a chlorine atom catalyzed by DMC. The successful preparation of cyclic guanidines resulted in uncovering further utility of DMC in organic synthesis.(9) |
|
