Silicon and tin 3-, 3, 5-, and 3, 4, 5-metalated pyrazoles have been synthesized by 1, 3- dipolar cycloadditions of silyl-, disilyl-, and silylstannylacetylenes with N-phenylsydnone or trimethylsilyldiazomethane. On the other hand, 1-and 2-pyrazolines monometalated and dimetalated in different positions of the heterocycle have been prepared by reaction of vinylsilanes and vinylstannanes with the same 1, 3-dipolar reagents. Other interesting ...
