Tandem One-Pot Synthesis of Polysubstituted NH-Pyrroles Involving the Palladium-Catalyzed Intramolecular Oxidative Amination of the Zinc Bromide Complex of β-Enamino Esters
作者:Ju Hyun Kim、Suh Young Choi、Jean Bouffard、Sang-gi Lee
DOI:10.1021/jo501672c
日期:2014.10.3
oxidative olefin amination of the zinc bromide complex intermediate, formed by the sequential reaction of nitriles with a Reformatsky reagent and 1-alkynes, affords pyrrole derivatives in good to excellent yields. This tandem protocol provides a simple, efficient, and atom- and pot-economical way to quickly build polysubstituted NH-pyrroles starting from readily available reagents in a regiocontrolled manner
腈与Reformatsky试剂和1-炔烃的顺序反应形成的溴化锌配合物中间体的Pd催化氧化烯烃胺化反应可提供高收率或优异收率的吡咯衍生物。该串联方案提供了一种简单,有效且原子经济的方法,可从易于获得的试剂开始,以区域可控的方式快速构建多取代的NH-吡咯,具有广泛的底物范围和较高的官能团耐受性。相反,分离的α-乙烯基-β-烯氨基酯的Pd催化氧化烯烃胺化反应没有有效进行,但是可以通过添加n -BuZnBr或Zn(OAc)2来恢复反应效率。,表明锌络合物在这种转化中的关键作用。通过选择性的Pd和Cu催化的C–C和C–O键形成反应,快速合成吡咯并菲和吡咯并吡咯,可以举例说明该方案的合成实用性。