Synthesis of 3,5-disubstituted pyridazines by regioselective [4+2] cycloadditions with ethynyltributyltin and subsequent replacement of the organotin substituent
作者:Jürgen Sauer、Dieter K. Heldmann
DOI:10.1016/s0040-4020(98)00127-6
日期:1998.4
Cycloadditions of 3-aryl-1,2,4,5-tetrazines 1a-o with ethynyltributyltin 5 occur with high regioselectivity to yield 3-aryl-5-tributylstannyl-pyridazines 9–23 in 71–95% yield. Moreover, the stannanes obtained could be utilized as starting materials for the preparation of various 3,5-di-substituted pyridazines as shown for 3-phenyl-5-tributylstannyl-pyridazine 9b. Stille cross-couplings with aryl halides