Dipyrromethane‐Based PGeP Pincer Germyl Rhodium Complexes

A family of germyl rhodium complexes derived from the PGeP germylene 2,2’‐bis(di‐isopropylphosphanylmethyl)‐5,5’‐dimethyldipyrromethane‐1,1’‐diylgermanium(II), Ge(pyrmP( i )Pr(2))(2)CMe(2) (1), has been prepared. Germylene 1 reacted readily with [RhCl(PPh(3))(3)] and [RhCl(cod)(PPh(3))] (cod=1,5‐cyclooctadiene) to give, in both cases, the PGeP‐pincer chloridogermyl rhodium(I) derivative [Rh{κ(3) P,Ge,P‐GeCl(pyrmP( i )Pr(2))(2)CMe(2)}(PPh(3))] (2). Similarly, the reaction of 1 with [RhCl(cod)(MeCN)] afforded [Rh{κ(3) P,Ge,P‐GeCl(pyrmP( i )Pr(2))(2)CMe(2)}(MeCN)] (3). The methoxidogermyl and methylgermyl rhodium(I) complexes [Rh{κ(3) P,Ge,P‐GeR(pyrmP( i )Pr(2))(2)CMe(2)}(PPh(3))] (R=OMe, 4; Me, 5) were prepared by treating complex 2 with LiOMe and LiMe, respectively. Complex 5 readily reacted with CO to give the carbonyl rhodium(I) derivative [Rh{κ(3) P,Ge,P‐GeR(pyrmP( i )Pr(2))(2)CMe(2)}(CO)] (6), with HCl, HSnPh(3) and Ph(2)S(2) rendering the pentacoordinate methylgermyl rhodium(III) complexes [RhHX{κ(3) P,Ge,P‐GeMe(pyrmP( i )Pr(2))(2)CMe(2)}] (X=Cl, 7; SnPh(3), 8) and [Rh(SPh)(2){κ(3) P,Ge,P‐GeMe(pyrmP( i )Pr(2))(2)CMe(2)}] (9), respectively, and with H(2) to give the hexacoordinate derivative [RhH(2){κ(3) P,Ge,P‐GeMe(pyrmP( i )Pr(2))(2)CMe(2)}(PPh(3))] (10). Complexes 3 and 5 are catalyst precursors for the hydroboration of styrene, 4‐vinyltoluene and 4‐vinylfluorobenzene with catecholborane under mild conditions.