Synthesis and structures of heterobimetallic Ir2M (MPd, Pt) sulfido clusters and their catalytic activity for regioselective addition of alcohols to internal 1-aryl-1-alkynes
摘要:
The heterobimetallic trinuclear sulfido clusters [(Cp*Ir)(2)(mu (3)-S)(2)MCl2] (M = Pd (3), Pt (4); Cp* = eta (5)-C5Me5) were synthesized from the dinuclear hydrogensulfido complex [Cp*IrCl(mu -SH)(2)IrCp*Cl] (2) and [MCl2(COD)] (COD = cycloocta-1,5-diene), while the reaction of 2 with [Pd(PPh3)(4)] afforded the cationic trinuclear cluster [(Cp*Ir)(2)(mu (3)-S)(2)PdCl(PPh3)]Cl (5). Clusters 3 and 4 reacted with PPh3 to give a series of mono and dicationic clusters including 5, while the dicationic clusters [(Cp*Ir)(2)(mu (3)-S)(2)M(dppe)][BPh4](2) (M = Pd (9), Pt (10); dppe = Ph2PCH2CH2PPh2) were obtained by the reaction with dppe followed by anion metathesis. The molecular structures of 5 . CH2Cl2, 9 . CH3COCH3, and 10 . CH3COCH3 were determined by X-ray crystallography. Clusters 3 and 4 were found to catalyze the addition of alcohols to alkynes to give the corresponding acetals. Internal 1-aryl-1-alkynes were transformed by cluster 3 into the corresponding 2,2-dialkoxy-1-arylalkanes with high regioselectivity up to 99:1, while cluster 4 was a much less regioselective catalyst. (C) 2001 Elsevier Science B.V. All rights reserved.
Synthesis and structures of heterobimetallic Ir2M (MPd, Pt) sulfido clusters and their catalytic activity for regioselective addition of alcohols to internal 1-aryl-1-alkynes
摘要:
The heterobimetallic trinuclear sulfido clusters [(Cp*Ir)(2)(mu (3)-S)(2)MCl2] (M = Pd (3), Pt (4); Cp* = eta (5)-C5Me5) were synthesized from the dinuclear hydrogensulfido complex [Cp*IrCl(mu -SH)(2)IrCp*Cl] (2) and [MCl2(COD)] (COD = cycloocta-1,5-diene), while the reaction of 2 with [Pd(PPh3)(4)] afforded the cationic trinuclear cluster [(Cp*Ir)(2)(mu (3)-S)(2)PdCl(PPh3)]Cl (5). Clusters 3 and 4 reacted with PPh3 to give a series of mono and dicationic clusters including 5, while the dicationic clusters [(Cp*Ir)(2)(mu (3)-S)(2)M(dppe)][BPh4](2) (M = Pd (9), Pt (10); dppe = Ph2PCH2CH2PPh2) were obtained by the reaction with dppe followed by anion metathesis. The molecular structures of 5 . CH2Cl2, 9 . CH3COCH3, and 10 . CH3COCH3 were determined by X-ray crystallography. Clusters 3 and 4 were found to catalyze the addition of alcohols to alkynes to give the corresponding acetals. Internal 1-aryl-1-alkynes were transformed by cluster 3 into the corresponding 2,2-dialkoxy-1-arylalkanes with high regioselectivity up to 99:1, while cluster 4 was a much less regioselective catalyst. (C) 2001 Elsevier Science B.V. All rights reserved.