189273-74-3Relevant academic research and scientific papers
The Hydroxyalkyl Moiety As a Protecting Group for the Stereospecific Alkylation of Masked Secondary Phosphine-Boranes
Lemouzy, Sébastien,Jean, Marion,Giordano, Laurent,Hérault, Damien,Buono, Gérard
supporting information, p. 140 - 143 (2016/01/15)
The synthesis of functionalized tertiary phosphine-boranes has been developed via a chemodivergent approach from readily accessible (hydroxymethyl) phosphine-boranes under mild conditions. O-Alkylation or decarbonylative P-alkylation product could be excl
Development of ruthenium catalysts for the enantioselective synthesis ofP-stereogenic phosphines via nucleophilic phosphido intermediates
Chan, Vincent S.,Chiu, Melanie,Bergman, Robert G.,Toste, F. Dean
, p. 6021 - 6032 (2009/09/24)
This work details the development of ruthenium(ll) catalysts for the enantioselective alkylation of chiral racemic secondary phosphines. The reactions proceed through the intermediacy of nucleophilic phosphido species, which have low barriers to pyramidal inversion; this allows for a dynamic kinetic asymmetric alkylation. The initially discovered [((R)-/Pr-PHOX) 2Ru(H)][BPh 4] (6) catalyst was found to be effective in the reaction with benzylic chlorides; moreover, the alkylation displayed an unusual temperature dependence. However, the limited scope of alkylation of 6 motivated further studies which led to the development of two complementary chiral mixed ligand Ru(ll) catalysts of type [L 1L 2Ru(H)] +. These catalysts were derived from a combination of one chiral and one achiral ligand, where a synergistic interaction of the two ligands creates an effective asymmetric environment around the ruthenium center. The (R)-MeO-BiPHEP/dmpe (dmpe= 1,2-bis(dimethylphosphino)ethane) catalyst (10) was found to be effec tive for the asymmetric alkylation of benzylic chlorides, while the (R)-DIFLUORPHOS/dmpe catalyst (11) was optimal for the nucleophilic substitution of less activated alkyl bromides; the scope of the respective catalysts was also explored.
Asymmetric catalytic synthesis of P-stereogenic phosphines via a nucleophilic ruthenium phosphide complex
Chan, Vincent S.,Stewart, Ian C.,Bergman, Robert G.,Dean Toste
, p. 2786 - 2787 (2007/10/03)
Ruthenium phosphido complexes have been shown to be excellent nucleophiles, reacting via two-electron processes with a variety of electrophiles. A catalytic alkylation reaction was developed using an achiral ruthenium complex, which was then elaborated into a catalytic enantioselective synthesis of P-stereogenic phosphines. These useful and synthetically challenging phosphines can now be accessed in a single step from simple secondary phosphines and alkyl halides. Optimization and scope of the enantioselective alkylation are discussed. Copyright
Study of the bonding properties of the new ligands C5H3N(2-R′)(6-CH2PPhR) toward rhodium(I). Evidence for a dynamic competition for bonding between O- and N-donor centers when R = o-Anisyl, R′ = Me
Yang, Hong,Lugan, No?l,Mathieu, René
, p. 2089 - 2095 (2008/10/08)
The bonding properties of the optically active chiral-at-P polydentate ligands C5H3N(2-R′)(6-CH2PPhR) (R = Me, R′ = H, Me; R = o-anisyl, R′ = H, Me) and the achiral ligand C5H3N(2-Me)(6-CH2PPh2) toward (COD)Rh+ are reported. The results show that steric hindrance of the 2-position of the pyridyl ring induces a labile character of the Rh-N bond. Moreover, for R = o-anisyl and R' = Me, a dynamic competition for bonding between the N-and O-donating centers is observed. Comparison of the solid state structures of complexes [Rh(COD)(C5H4N(2-CH2PPhMe)][BF4] and [Rh(COD)(C5H3N(2-Me)(6-CH2PPh 2)][BF4] shows a significant bond lengthening of the Rh-N bond in the latter complex, consistent with its fluxional behavior observed in solution.
