Stoichiometric and catalytic Sn-mediated dehydrocoupling of primary phosphines

Abstract

The room-temperature reactions of stannocene, Cp*(2)Sn, with a range of primary phosphines, RPH(2), result in diphosphanes [RP(H)P(H)R]. The reactions involving Cp*(2)SnCl(2), however, result in catalytic dehydrocoupling; the first example of main group metal catalysed dehydrocoupling to be identified.

Synthesis and characterization of zinc complexes and reactivity with primary phosphines

“…Though zinc complexes would not be expected to demonstrate the same kinds of reactivity as formally d 8 and d 0 metal complexes, which are demonstrated phosphine dehydrocoupling catalysts [8], the recent report of a tin complex, Cp* 2 SnCl 2 , that is a catalyst for dehydrocoupling prompts the study of alternative metal species [14].…”

Dehydrogenative Bond-Forming Catalysis Involving Phosphines: Updated Through 2010

“…Interestingly, this reaction requires the tin(IV) precursor. Reaction of decamethylstannocene with the same phosphine substrates gave diphosphine but only stoichiometrically at a 2:1 phosphine:tin ratio [84]. This initial result suggests that a new area of main-group element catalyzed dehydrocoupling is possible.…”

“…Wright and coworkers have recently made a significant breakthrough in this regard with the report of organotin complexes as catalysts for the dehydrocoupling of phosphines [84]. In particular, it was found that decamethylstannocene dichloride (Cp* 2 SnCl 2 ) dehydrocoupled primary phosphines, RPH 2 , where R = t Bu, Cy, or ferrocenyl (Fc) to predominately the diphosphine product with some formation of the four-and five-membered rings (eq.…”

Terminal Phosphanido Rhodium Complexes Mediating Catalytic PP and PC Bond Formation

“…[9] More recently, main-group reagents such as [Sn (C 5 Me 5 ) 2 Cl 2 ] have been reported to be suitable catalysts for PÀP bond formation, although with modest TON values. [10] Detailed mechanistic information on the dehydrocoupling of phosphanes only exists in a few cases, mainly concerning early transitionmetal catalysts.…”

“…[9] More recently, main-group reagents such as [Sn (C 5 Me 5 ) 2 Cl 2 ] have been reported to be suitable catalysts for PÀP bond formation, although with modest TON values. [10] Detailed mechanistic information on the dehydrocoupling of phosphanes only exists in a few cases, mainly concerning early transitionmetal catalysts. [2b, 11] Nonetheless, the Rh V diphosphanide species [Rh (C 5 Me 5 )(H) 2 (PR 2 ) 2 ] was tentatively hypothesized by Bçhm and Brookhart to mediate in the dehydrocoupling of secondary phosphanes, [9b] while [Rh(dippe)(CH 2 Ph)(H)-(PHPh)] (dippe = iPr 2 PCH 2 CH 2 PiPr 2 ) was observed as a transient species in the preparation of the dinuclear complex [{Rh(m-PHPh)(dippe)} 2 ] as a precatalyst for dehydrocoupling primary phosphanes.…”