Asymmetric organocatalytic synthesis of tertiary azomethyl alcohols: key intermediates towards azoxy compounds and α-hydroxy-β-amino esters
作者:José A. Carmona、Gonzalo de Gonzalo、Inmaculada Serrano、Ana M. Crespo-Peña、Michal Šimek、David Monge、Rosario Fernández、José M. Lassaletta
DOI:10.1039/c7ob00308k
日期:——
synthesized and their behavior as bifunctional organocatalysts has been tested in the enantioselective nucleophilic addition of formaldehyde tert-butyl hydrazone to aliphatic α-keto esters for the synthesis of tertiary azomethyl alcohols. Using the 1,3,4,6-tetra-O-acetyl-2-amino-2-deoxy-β-D-glucosamine derived 3,5-bis-(trifluoromethyl)phenyl thiourea the reaction could be accomplished with high yields
已经合成了一系列过酰基化的氨基糖衍生的硫脲,并且已经在甲醛叔丁基向脂肪族α-酮酯的对映选择性亲核加成反应中合成了偶氮叔甲基醇,对它们作为双功能有机催化剂的行为进行了测试。使用1,3,4,6-四-O-乙酰基-2-氨基-2-脱氧-β - D-葡糖胺衍生的3,5-双-(三氟甲基)苯基硫脲可以高收率地完成反应( 75–98%)和中等对映选择性(50–64%ee)。随后以单锅方式对芳族和脂族取代的重氮产品进行高产率且无消旋的转化,可直接进入有价值的氮氧基化合物和α-羟基-β-氨基酯。