作者:Lei, Xingyu、Wang, Yihan、Ma, Shanshan、Jiao, Peng
DOI:10.1021/acs.joc.4c00525
日期:——
cycloalkyl, aryl, heteroaryl, pyridyl, and alkynyl Grignard reagents were compatible with the protocol. As a result, alkyl- and arylpyridines and 2,2′-bipyridines were easily prepared. Single electron transfer from the Grignard reagent to bromopyridine was stimulated by purple light. An electron extruded from the dimerization of the Grignard reagent worked as the catalyst. Light on/off experiments indicated
烷基吡啶和芳基吡啶以及2,2'-联吡啶通常通过吡啶的Minisci反应和卤代吡啶的过渡金属催化的偶联反应来制备。在此,首次公开了在普通玻璃器皿中的Et 2 O或Et 2 O与四氢呋喃的混合物中,紫光促进的2-或4-溴吡啶与格氏试剂的自由基偶联反应,而不需要过渡金属催化剂。甲基、伯烷基和仲烷基、环烷基、芳基、杂芳基、吡啶基和炔基格氏试剂与该方案兼容。结果,很容易制备烷基吡啶和芳基吡啶以及2,2'-联吡啶。紫光刺激从格氏试剂到溴吡啶的单电子转移。格氏试剂二聚过程中挤出的电子充当催化剂。光开/关实验表明产物的形成需要持续的照射。自由基时钟底物的研究证实了来自溴吡啶的吡啶基自由基的参与以及来自格氏试剂的烷基或芳基自由基的不参与。现有证据支持新偶联反应的光诱导 S RN机制。