M. Mori et al., UTILIZATION OF ME3SISNBU3 IN ORGANIC-SYNTHESIS .1. GENERATION OF A STANNYL ANION FROM ME3SISNBU3 AND R4NX, Journal of organometallic chemistry, 455(1-2), 1993, pp. 255-260
A metal free stannyl anion generated from Me3SiSnBu3 and R4NX in DMF r
eacted with an aryl halide bearing carbonyl group to produce an aryl a
nion via the so-called halogen-metal exchange process, which reacted w
ith a carbonyl group to afford a cyclized product in good yield.