Synthesis of bis(diphenylphosphinio) octahydro-closo-decaborates L_2B_(10)H_8 (L = Ph_2PH) and 1-(diphenylphosphinio)-nonahydro-closo-decaborates(1-) [1-LB_(10)H_9]~- (L = Ph_2pH, PH_2P(OH)) by the palladium-catalyzed reaction of ph_2pH with 1-diazon

摘要

(PPh_3)_2 PdCl_2 and Cul, used in low concentration as catalysts, favour the replacement of the diazo group of [1-N_2B_(10)H_9]~- by Ph_2PH. Owing to its instability [1-(Ph_2PH)B_(10)H_9]~- could not be isolated in a pure form and was obtained as a mixture with [1-Ph_2P(OH)B_(10)H_9]~-, but pure samples of [1-Ph_2P(OH)B_(10)H_9]~- were easily obtainable. (PPh_3)_2 PdCl_2 also acted as a reactant, the reduction of Pd(II) to Pd(0) allowing the formation of the neutral substituted boranes 1,6-(Ph_2PH)_2B_(10)H_8 and 1, 10-(Ph_2PH)_2B_(10)H_8. These two isomers were separated by chromatography. All the products were characterized by ~(11)B and ~(31)P NMR and mass spectrometry techniques.