Diastereoselectivity in the triethylamine-catalyzed sulfa-Michael addition of thiols to nitroalkenes: kinetic and thermodynamic control
作者:Jiandong Wang、Ning Chen、Jiaxi Xu
DOI:10.1016/j.tet.2015.04.053
日期:2015.6
sulfa-Michael addition of nitroalkenes and thiols was investigated. The sulfa-Michael addition is kinetic control at the beginning and thermodynamic control at the end for less bulky reactants. Thus, kinetic and thermodynamic-controlled adducts can be obtained as major products by controlling the reaction time in those cases. Linear nitroalkenes generally produce anti-adducts as major kinetic products due
研究了三乙胺催化的磺基-迈克尔加成硝基烯烃和硫醇的非对映选择性。磺胺-迈克尔加成反应从一开始就是动力学控制,最后是热力学控制,以减少体积较大的反应物。因此,在这些情况下,通过控制反应时间,可以得到动力学和热力学控制的加合物作为主要产物。线性硝基烯烃一般产生抗由于有利的空间和立体电子效应-adducts作为主要的动力学的产品,但非对映选择性与位于邻位烯属碳的硝基的取代基的空间位阻的增加明显降低,甚至导致顺式加成物作为主要的动力学产品。1-硝基环己烯使顺式-加合物,其差向异构化成更稳定的反式-加合物通过热力学平衡主要产物。但是,涉及大反应物的迈克尔加成反应通常较慢,导致直接产生热力学加合物。