Main observation and conclusion Herein,we describe a novel catalytic Pictet-Spengler-type cyclization using CO_(2) as a nontoxic and sustainable C1 feedstock with envi-ronmentally benign and non-precious-metal iron as...Main observation and conclusion Herein,we describe a novel catalytic Pictet-Spengler-type cyclization using CO_(2) as a nontoxic and sustainable C1 feedstock with envi-ronmentally benign and non-precious-metal iron as catalyst.The reaction is achieved by selective four-electron reduction of CO_(2) into methylene level intermediate through carefully tuning the reaction parameters.A variety of tetrahydro-B-carbolines and other nitro-gen-containing heterocycles can be easily obtained under mild conditions.Mechanistic studies have shown that tetrahy-dro-B-carbolines are probably obtained via spiroindolenine intermediates.展开更多
A new approach for radical cross coupling of organic halides and oxalates toward esters has been developed via photoredox nickel dual catalysis.This method has been demonstrated for transformation of a wide range of a...A new approach for radical cross coupling of organic halides and oxalates toward esters has been developed via photoredox nickel dual catalysis.This method has been demonstrated for transformation of a wide range of aryl,heteroaryl,alkenyl,and alkyl bromides to various esters under mild conditions.Notably,fluoro-,chloro-,or iodo-substituents on the aryl bromides remain after the coupling reaction,which has been applied for the easy synthesis of drug molecules from simple aryl dihalides.Mechanistic studies indicate that an(alkoxycarbonyl)Ni(I)species might be generated via oxidation of Ni(0)species with an alkoxycarbonyl radical intermediate.Selective alkoxycarbonyl radical coupling over decarboxylative alkyl radical coupling is achieved here.展开更多
基金We are grateful to the financial support from NSFC(Nos.21772208,21702212,21602230)the Key Research Program of Frontier Sciences of CAS(No.QYZDJSSW-SLH051).
文摘Main observation and conclusion Herein,we describe a novel catalytic Pictet-Spengler-type cyclization using CO_(2) as a nontoxic and sustainable C1 feedstock with envi-ronmentally benign and non-precious-metal iron as catalyst.The reaction is achieved by selective four-electron reduction of CO_(2) into methylene level intermediate through carefully tuning the reaction parameters.A variety of tetrahydro-B-carbolines and other nitro-gen-containing heterocycles can be easily obtained under mild conditions.Mechanistic studies have shown that tetrahy-dro-B-carbolines are probably obtained via spiroindolenine intermediates.
基金the financial support from the NSFC of China(21772208 and 21633013)Natural Science Foundation of Jiangsu Province(BK20201183)the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(QYZDJSSW-SLH051).
文摘A new approach for radical cross coupling of organic halides and oxalates toward esters has been developed via photoredox nickel dual catalysis.This method has been demonstrated for transformation of a wide range of aryl,heteroaryl,alkenyl,and alkyl bromides to various esters under mild conditions.Notably,fluoro-,chloro-,or iodo-substituents on the aryl bromides remain after the coupling reaction,which has been applied for the easy synthesis of drug molecules from simple aryl dihalides.Mechanistic studies indicate that an(alkoxycarbonyl)Ni(I)species might be generated via oxidation of Ni(0)species with an alkoxycarbonyl radical intermediate.Selective alkoxycarbonyl radical coupling over decarboxylative alkyl radical coupling is achieved here.
