1: bis-diphenylphosphine With cesium hydroxide monohydrate in N,N-dimethyl-formamide T=20°C; 1 h; Molecular sieveInert atmosphere; 2: bromoform in N,N-dimethyl-formamide T=20°C; 48 h; Inert atmosphereMolecular sieve;

potassium hydroxide; tetrabutylammomium bromide in dimethyl sulfoxide 2 h; Heating;

potassium tert-butylate Heating; Yield given;

in tetrahydrofuran N2 atmosphere; treatment of Pt-complex with equiv. amt. of Ph2PCH=CHPPh2 (IR minitoring, 10 days); pptn. on redn. of vol. and n-hexane addn.;