trimethylsilyl trifluoromethanesulfonate; bis(1,5-cyclooctadiene)nickel (0) in dichloromethane (N2 or Ar); trimethylsilyl trifluoromethanesulfonate added to a soln. ofSn compd. and C2H5CH(OCH3)2 in CH2Cl2, stirred at -40°C, a satd. aq. soln. of Na2CO3 added at -40°C, allowed to warm to room temp ., treated with a solid K2CO3,; a soln. of Ni complex in toluene and 1,2-heptadiene added, stirred at room temp. for 1 h, filtered, concd., chromd. (preparative GPC);