Zur Reaktion von Metall-koordinierten Kohlenmonoxid mit Yliden XXII. Bis(diphenylphosphino)methanid-Eisen-Komplexe Cp(L)Fe(Ph2PCHPPh2) (L = CO, Me3P)

Synthesis and Nucleophilic Behavior of cis-[M(C6F5)2(Ph2PCHPPh2)]- (M = Pd, Pt): C-Alkylation, Metalation, and Halogenation of Coordinated Bis(diphenylphosphino)methane. X-ray Crystal Structure of [Pt(C6F5)2(Ph2PCHIPPh2)]·C5H12

“…The dialkylated complexes [M(C 6 F 5 ) 2 (Ph 2 PCMe 2 PPh 2 )] [M = Pd ( 3a ), Pt ( 3b )], which were obtained as impurities in the synthesis of 2a and 2b , were not isolated in pure form, but they were characterized spectroscopically by 1 H and 31 P{ 1 H} NMR (see Table ). The 31 P{ 1 H} NMR spectra show a single resonance shifted downfield with respect to 2a or 2b by nearly the same displacement as that found for the complexes M(CO) 4 (dppm-Me 2 ) (M = Cr, Mo, W) 5c or PtX 2 (dppm-Me 2 ) 5c. The 1 H NMR spectra show a triplet resonance (about 1.5 ppm) attributed to the CMe 2 unit.…”

“…The 31 P{ 1 H} NMR spectra of both complexes (see Table ) show a single resonance, with 195 Pt satellites for 2b , slightly broadened due to the presence of the trans -C 6 F 5 groups. This resonance has undergone a downfield shift with respect to the starting dppm compounds 1a or 1b of the same magnitude as that observed for the complexes M(CO) 4 (dppm-Me) (M = Cr, Mo, W) 5c or PtX 2 (dppm-Me) 5c…”

“…One of the most interesting applications of the complexes containing the methanide form arises from their use as intermediates in the synthesis of complexes with functionalized dppm, since it has been shown that the treatment of the free ligand salts [Li(Ph 2 PCHPPh 2 )] with electrophiles generally gives mixtures of products resulting from attack on carbon and phosphorus atoms. For instance, complexes with C-alkylated dppm have been reported, and only very recently have halogenation reactions of the coordinated [Ph 2 PCHPPh 2 ] - been described in which, in almost all cases, carbonyl derivatives of transition metals with low oxidation numbers have been used. Despite this, the use of bis(diphenylphosphino)methanide complexes of M II (M = Pd, Pt) in alkylation reactions has barely been examined, 5c,f and, as far as we know, there are no examples of halogenation and/or metalation reactions.…”

“…For instance, complexes with C-alkylated dppm have been reported, and only very recently have halogenation reactions of the coordinated [Ph 2 PCHPPh 2 ] - been described in which, in almost all cases, carbonyl derivatives of transition metals with low oxidation numbers have been used. Despite this, the use of bis(diphenylphosphino)methanide complexes of M II (M = Pd, Pt) in alkylation reactions has barely been examined, 5c,f and, as far as we know, there are no examples of halogenation and/or metalation reactions.…”

New chemical and stereochemical applications of organoiron complexes

“…Additional carbon-carbon bond formations are: synthesis of [Fe 2 (CO) 6 (η-C(OR)H)(η-CR′ = CR′H)] − anions (R = Me, Et; R′ = Ph, H) (at a dinculear iron center) [ 1027 ], synthesis of a new tert -butylnitroso complex [CpFe(CO)(PPh 3 )N(O) tert -Bu] + (Cp=η 5 -C 5 H 5 ) [ 1028 ], synthesis of a new bis(phosphino)methanideiron complex Cp(CO)Fe(Ph 2 PCH PPh 2 ) [ 1029 ]; also preparation of derivatives from doubly-bridged diiron complexes of the type [(η-η 2 -ROC(1)S)Fe 2 (CO) 6 (η-SMe)] (via ligand-exchange reactions) [ 1030 ], synthesis of cycloheptatriene complexes (η 3 -C 7 H 7 )Fe(CO) 3 EPh 3 (E = Sn, Pb) [ 1031 ], and synthesis of benzophenones through carbonylation of aryl iodides catalyzed by the Fe(CO) 5 -CO 2 (CO) 8 system [ 1032 ].…”