提供线性或支化产物的环氧化物的开环属于有机合成中的经典转化组。然而,芳基环氧化物与芳基卤化物的区域选择性交叉亲电偶联仍然是一个关键挑战。在此,我们报告了维生素 B 12 /Ni 双催化系统允许在蓝光照射下选择性合成线性产物,从而补充获得支化醇的方法。实验和理论研究证实了所提出的涉及烷基钴胺素作为该反应中间体的机制。
Photocatalytic carbanion generation – benzylation of aliphatic aldehydes to secondary alcohols
作者:Karsten Donabauer、Mitasree Maity、Anna Lucia Berger、Gregory S. Huff、Stefano Crespi、Burkhard König
DOI:10.1039/c9sc01356c
日期:——
present a redox-neutral method for the photocatalytic generation of carbanions. Benzylic carboxylates are photooxidized by single electron transfer; immediate CO2 extrusion and reduction of the in situ formed radical yields a carbanion capable of reacting with aliphatic aldehydes as electrophiles giving the Grignard analogous reaction product.
Ring-opening of epoxides furnishing either linear or branched products belongs to the group of classic transformations in organic synthesis. However, the regioselective cross-electrophile coupling of aryl epoxides with aryl halides still represents a key challenge. Herein, we report that the vitamin B12/Ni dual-catalytic system allows for the selective synthesis of linear products under blue-light
提供线性或支化产物的环氧化物的开环属于有机合成中的经典转化组。然而,芳基环氧化物与芳基卤化物的区域选择性交叉亲电偶联仍然是一个关键挑战。在此,我们报告了维生素 B 12 /Ni 双催化系统允许在蓝光照射下选择性合成线性产物,从而补充获得支化醇的方法。实验和理论研究证实了所提出的涉及烷基钴胺素作为该反应中间体的机制。