Chemistry of CS₂- and SCNPh-adducts of the pyramidal phosphinidene-bridged complex [Mo₂Cp(μ–κ¹:κ¹,η⁵-PC₅H₄)(CO)₂(η⁶-HMes*)(PMe₃)]

Abstract

The title complex reacted readily with CS 2 and SCNPh to give the phosphinidenecumulene adducts [Mo 2 Cp{-

P–N and N–Mo Bond Formation Processes in the Reactions of a Pyramidal Phosphinidene-Bridged Dimolybdenum Complex with Diazoalkanes and Organic Azides

“…106 o ). This is also reflected in the observation, for the corresponding 13 C NMR resonances, of a relatively high coupling of ca. 28 Hz with both P atoms of the molecule.…”

“…10 To further explore the complex reactivity of pyramidal phosphinidene complexes towards azides and diazoalkanes, we decided to study the reactivity of the dimolybdenum complex [Mo2Cp(- 1 : 1 , 5 -PC5H4)(CO)2( 6 -HMes*)(PMe3)] (1, Chart 2) towards these unsaturated organic molecules, which is the purpose of the present work. Previous studies have revealed that 1 displays a strong nucleophilicity that enables it to react under mild conditions with different C-based electrophiles such as organic anhydrides, 11 alkyl halides, 12 and S-containing cumulenes, 13 among other electrophiles. Thus, it could be anticipated that 1 might easily react with organic azides and diazoalkanes, although the subsequent evolution of the products following the initial PN bond formation step would be harder to predict, particularly because of the very different electronic environments of the Mo centers bound to the phosphinidene ligand in this molecule.…”

“…9 Interestingly, reorganization of the diazoalkane derivatives could only be induced upon photochemical decarbonylation of the products first formed, which in most cases involved no denitrogenation but gave complexes with phosphadiazadiene ligands displaying novel P,C-and P,N-bound coordination modes, such as those shown in Scheme 4, among other unusual products. 10 To further explore the complex reactivity of pyramidal phosphinidene complexes toward azides and diazoalkanes, we decided to study the reactivity of the dimolybdenum complex revealed that 1 displays a strong nucleophilicity that enables it to react under mild conditions with different C-based electrophiles such as organic anhydrides, 11 alkyl halides, 12 and S-containing cumulenes, 13 among other electrophiles. Thus, it could be anticipated that 1 might easily react with organic azides and diazoalkanes, although the subsequent evolution of the products following the initial P−N bond formation step would be harder to predict, particularly because of the very different electronic environments of the Mo centers bound to the phosphinidene ligand in this molecule.…”

“…Nuclear magnetic resonance (NMR) spectra were routinely recorded at 295 K in CD2Cl2 solution unless otherwise stated. Chemical shifts () are given in ppm, relative to internal tetramethylsilane ( 1 H,13 C), or external 85% aqueous H3PO4 solutions ( 31 P). Coupling constants (J) are given in hertz.…”

Flexible Synthesis of Phosphoryl-Substituted Imidazolines, Tetrahydropyrimidines, and Thioamides by Sulfur-Mediated Processes

“…Tetrahydropyrimidines bearing a phosphoryl group are highly promising ligands for transition metal complexes . Phosphoryl thioamides have found broad applications as ligands for metal cations, polymerization initiators, hybrid materials building blocks, and multifunctional reagents . In recent years organophosphorus compounds have gained significant attention in organic synthesis, but convenient and valuable synthetic approaches for their preparation are still required .…”