Dipyrromethane‐Based PGeP Pincer Germyl Rhodium Complexes
Javier A. Cabeza, José M. Fernández‐Colinas, Joaquín García‐Álvarez, Pablo García‐Álvarez, Carlos J. Laglera‐Gándara, Marina Ramos‐Martín
Abstract
Abstract 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.