Monophosphine and diphosphine ligands for diplatinum polyynediyl complexes: Efficient syntheses of new functionality-containing systems and model compounds

Br(CH2)(4)Br and NaO(CH2)(2)CH=CH2 react under suitable conditions to give Br(CH2)(4)O(CH2)(2)CH=CH2 (55%), which is treated with KPPh2 to yield the ether-containing phosphine Ph2P(CH2)(4)O(CH2)(2)CH=CH2 (83%), The reaction of CH3CH2OC(O)CH=C(CH3)(2) and BrMg(CH2)(3)CH=CH2 in the presence of CuCl (cat.) and ClSiMe3 yields CH3CH2OC(O)CH2C(CH3)(2)(CH2)(3)CH=CH2 (67%), which is reduced to an alcohol that is brominated, reacted with Grubbs' catalyst, hydrogenated, and treated with KPPh2 to give the bis(geminally dimethylated) diphosphine Ph2P(CH2)(2)C(CH3)(2)(CH2)(8)C(CH3)(2)(CH2)(2)PPh2 (47%, overall). The photochemical reaction of I(CF2)(8)I and H2C=CHCH2SnBu3 yields H2C=CHCH2(CF2)(8)CH2CH=CH2 (52%), which is converted with 9-BBN to a diol (92%) that is brominated and treated with LiPR2 to give the fluorinated diphosphines R2P(CH2)(3)(CF2)(8)(CH2)(3)PR2 (R = a, p-tol, 67%; b, t-Bu, 69%; c, o-tol, 86%). Reactions of Br(CH2)(m)Br and LiPR2 similarly yield R2P(CH2)(m)PR2 (m/R = 8/a, 95%; 14/a, 96%; 14/p-C6H4-t-Bu, 98%). Reactions of KPPh2 with Br(CH2)(m),CH=CH2 and Br(CH2)(7)CH3 give the corresponding monophosphines Ph2P(CH2)(m)'CH=CH2 (m' = 7, 82%; 10, 84%) and Ph2P(CH2)(7)CH3 (85%). When the former is combined with [Pt(mu-Cl)(C6F5(tht)](2) (tht = tetrahydrothiophene), trans-(C6F5)(Ph2P(CH2)(m),CH=CH2)(2)PtCl (77-70%) is isolated. When the latter (excess) is combined with trans,trans-(C6F5)(p-tol(3)P)(2)Pt(C C)(4)Pt(Pp-tol(3))(2)(C6F3) (RT, 65 degrees C) trans,trans-(C6F5)(Ph2P(CH2)(7)CH3)(2)Pt(C C)(4)Pt(Ph2P(CH2)(7)CH3)(2)(C6F5) (53%) is isolated. (c) 2006 Elsevier B.V. All rights reserved.