Self-Replication of Chelating Diphosphines via Pt(0)-Catalyzed Hydrophosphination

Abstract

The air-stable, functionalized diphosphine Ph2PCH2CH2P­(CH2CH2CO2Me)2 (L1) is the ligand for the Pt(0) complex that efficiently catalyzes the production of L1 from Ph2PCH2CH2PH2 and methyl acrylate. The mechanism proposed for this catalysis is consistent with the following observations: (1) the only product detected upon treatment of [Pt­(nbe)3] (nbe = η2-norbornene) with L1, even in the ratio Pt:L1 of 10:1, is the bis­(chelate) complex [Pt­(κ2-L1)2]; (2) complex 1 reacts with Ph2PCH2CH2PH2 to release L1; (3) complex 1 does not react with CH2CHCO2Me even when an excess of acrylate is present in high concentration; (4) the Pt(0)-catalyzed deuterophosphination of CH2CHCO2Me by Ph2PCH2CH2PD2 produced exclusively the isotopologue Ph2PCH2CH2P­(CH2CHDCO2Et)2 (L1-d 2) as a mixture of diastereoisomers; (5) in a competition experiment, CH2CHCO2Me reacted significantly more rapidly with Ph2PCH2CH2PH2 than with Ph2PCH2CH2PD2. The scope of this Pt(0)-catalyzed process has been extended to Ph2PCH2CH2P­(CH2CH2Z)2 (Z = CO2Et, CO2 t Bu, CN, CONH2, CONMe2), and it has the potential to be a general, atom-efficient route to many other functionalized diphosphines.

Synthesis of γ-cyclodextrin substituted bis(acyl)phosphane oxide derivative (BAPO-γ-CyD) serving as multiple photoinitiator and crosslinking agent

“…In a straightforward reaction, bis(2,4,6-trimethylbenzoyl)hydrogenphosphane (BAP-H, 4), which is in equilibrium with its tautomer, (MesCO)PQC(OH)Mes, 18,19,24 was added in the next step stereoselectively to the terminal carbon center of the CQC double bonds of 3 (phospha-Michael addition). [25][26][27][28][29][30][31] Subsequent oxygenation with aqueous H 2 O 2 leads to the phosphaneoxide BAPO-g-CyD (5) in high isolated yield (495%). Two closely lying 13 (Fig.…”

Metal-Catalyzed P–C Bond Formation via P–H Oxidative Addition: Fundamentals and Recent Advances

“…Although bis­(chelate) complex 53 was formed, it underwent rapid ligand substitution with P–H-containing substrates. As in Scheme , addition of t -butyl alcohol suppressed formation of oligomeric impurities, consistent with an outer-sphere mechanism for P–C bond formation …”

“…As in Scheme 16, addition of tbutyl alcohol suppressed formation of oligomeric impurities, consistent with an outer-sphere mechanism for P−C bond formation. 52 In a similar process, Rh(IPr)-catalyzed addition of diphenylphosphine to phenylacetylene resulted in double hydrophosphination to form a bidentate ligand (Scheme 22). The catalyst resting state contained two diphenylphosphines.…”

Metal-Catalyzed Hydrophosphination

“…Pringle and coworkers developed a protocol for the selfreplication of chelating diphosphines via platinum-catalyzed hydrophosphination. [109] Bidentate phosphines such as Ph2PCH2CH2P(CH2CH2R)2 were prepared from the reaction of Ph2PCH2CH2PH2 with electron deficient alkenes (Scheme 41). The catalyst is very efficient despite the possibility of chelating diphosphines poisoning catalysis (i.e., product inhibition).…”