Phosphorus-carbon bond cleavage and tetrahedrane cluster activation in the reaction between bis(diphenylphosphino)maleic anhydride (BMA) and PhCCo3(CO)9. Syntheses, kinetic studies, and x-ray diffraction structures of PhCCo3(CO)7(bma) and [cyclic] Co3(CO)6(.mu.2-.eta.2,.eta.1-C(Ph)C:C(PPh2)C(O)OC(O))(.mu.2-PPh2)

Abstract

Phosphorus-Carbon Bond Cleavage and TetrahedraneCluster Activation in the Reaction between Bis(diphenylphosphino)maleic Anhydride (BMA) and PhCCo3(CO)9. Syntheses, Kinetic Studies, and X-ray Diffraction Structures of PhCCo3(CO)7(bma) and Co3(CO)6(M2V,V-C(Ph)C=C(PPh2)C(0)OC( 0))(M2-PPh2

Non-innocent bma ligand in a dissymetrically disubstituted diiron dithiolate related to the active site of the [FeFe] hydrogenases

“…1). Formation of 1 could result from a well-known P-C bond cleavage in the bma ligand [28,29,32] and a formal, scarce C-H bon activation of a methyl group in Me 3 N [38,39]. To the best of our knowledge, few examples of C-H bond activation in tertiary amines were previously reported [38][39][40].…”

“…Numerous functionalities with specific electronic and steric effects could be introduced in diiron systems through these chelating groups [26,27]. In light of this, we decided to use the 2,3-bis (diphenylphosphino) maleic anhydride (bma) [28][29][30][31][32][33][34] to prepare a diiron compound holding a chelating redox-active ligand as a surrogate of the [4Fe4S] cubane. As compared to 1,2-bis(diphenylphosphino)ethane (dppe, Ph 2 PCH 2 CH 2 PPh 2 ) or 1,2-bis(diphenylphosphino)ethylene (dppv, Ph 2 PCH = CHPPh 2 ), bma exhibits a radically different electronic behavior because of a low-lying π*orbital delocalized over the maleic anhydride ring [30,31].…”

Regiospecific and sequential P–C bond activation/cluster transformations in the reaction of PhCCo2MoCp(CO)8 with the diphosphine ligands 2,3-bis(diphenylphosphino)maleic anhydride (bma) and 3,4-bis(diphenylphosphino)-5-methoxy-2(5H)-furanone (bmf)

“…The reaction of the diphosphine ligands 2,3-bis(diphenylphosphino)maleic anhydride (bma) and 3,4-bis(diphenylphosphino)-5-methoxy-2(5H)-furanone (bmf) with the tetrahedrane clusters RCCo 3 (CO) 9 (R = Ph, Fc) and RCCo 2 NiCp(CO) 6 (R = Ph, H) has been actively investigated by our groups the last several years [1][2][3][4]. The structures of these rigid diphosphine ligands are shown to the right.…”

“…The course and outcome of these reactions depend on several variables, one of which is the metallic composition of the cluster, as shown in Scheme 1 for the phenyl-capped clusters PhCCo 3 (CO) 7 (bma) and PhCCo 2 NiCp(CO) 4 (bma). Thermolysis of the bma-substituted Co 3 and Co 2 Ni clusters furnishes the structurally different phosphido-bridged clusters Co 3 (CO) 6 [l 2 ,g 2 ,g 1 [6] clusters have been shown to be stable under conditions comparable to those used to promote the transformations illustrated in Scheme 1. The synthesis and reactivity of the chiral clusters HCCo 2 NiCp(CO) 4 (bmf) and PhCCo 2 NiCp(CO) 4 (bmf) have recently been described by us [4].…”

“…The important role played by the capping R-group in controlling the chemistry exhibited by these bmf-substituted clusters was verified during routine thermolysis studies of HCCo 2 NiCp(CO) 4 (bmf) and PhCCo 2 NiCp(CO) 4 (bmf). Whereas heating PhCCo 2 NiCp(-CO) 4 (bmf) at 83°C leads to cluster decomposition, the latter methylidyne cluster undergoes a regiospecific cleavage of one of the two distinct P-C(furanone) bonds, followed by diastereoselective formation of the phosphido-bridged cluster Co 2 NiCp(CO) 4 [l 2 ,g 2 ,g 1 …”