Regioselective functionalization of trisubstituted pyridines using a bromine–magnesium exchange
作者:Hongjun Ren、Paul Knochel
DOI:10.1039/b515168f
日期:——
A tosyloxy substituent in position 2 allows a highly regioselective Br/Mg exchange reaction on 3,5-dibromopyridine derivatives using iso-PrMgCl.LiCl. The resulting functionalized pyridylmagnesium reagents react with various electrophiles in position 3. Acylated pyridines of this type can be readily converted into pyrazolo [3,4-b] pyridines.
2位的甲苯磺酰基取代基允许使用iso-PrMgCl.LiCl对3,5-二溴吡啶衍生物进行高度区域选择性的Br / Mg交换反应。所得的官能化的吡啶基镁试剂与3位上的各种亲电试剂反应。这种类型的酰基化吡啶可以容易地转化为吡唑并[3,4-b]吡啶。