Department of Chemistry, Indian Institute of Technology Ropar, Nangal Road, Rupnagar, Punjab-140001, India.
Org Biomol Chem. 2020 Aug 26;18(33):6564-6570. doi: 10.1039/d0ob01514h.
Typically, transition metal catalysis enforces the stereodefined outcome of a reaction. Here we disclose the palladium-catalyzed regio- and stereoselective access to allylic ureas/carbamates and their further exploitation to diverse cyclic structures under operationally simple reaction conditions. This protocol features palladium-catalyzed decarboxylative amidation of highly modular VECs with good to excellent yield, minimal waste production, wide substrate scope, and low catalyst loading. In follow-up chemistry, we demonstrated the debenzylation of vinylic imidazolidinones to N-hydroxycyclic ureas and regioselective derivatization towards the facile synthesis of halohydrins and oxiranes under mild reaction conditions in good to excellent yields.
通常情况下,过渡金属催化可以控制反应的立体化学结果。在这里,我们披露了钯催化的区域和立体选择性方法,可在操作简单的反应条件下,从烯丙基脲/氨基甲酸酯获得不同的环状结构。该方案的特点是钯催化的高模块化 VEC 的脱羧酰胺化,具有良好至优异的收率、最小的废物生成、广泛的底物范围和低催化剂负载。在后续的化学中,我们展示了通过去苄基化乙烯基咪唑烷酮得到 N-羟基环脲,以及在温和反应条件下通过区域选择性衍生化,以良好至优异的收率轻松合成卤代醇和环氧化物。