127686-90-2Relevant articles and documents
Reduction of phosphine oxides to phosphines with the InBr3/TMDS system
Pehlivan, Leyla,Métay, Estelle,Delbrayelle, Dominique,Mignani, Gérard,Lemaire, Marc
, p. 3151 - 3155 (2012)
An efficient method for the reduction of phosphine oxide derivatives into their corresponding phosphines is described. The system InBr3/TMDS allows the reduction of different secondary and tertiary phosphine oxides as well as aliphatic and aromatic phosphine oxides.
A Lewis Base Nucleofugality Parameter, NFB, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics
Taylor, Nicholas P.,Gonzalez, Jorge A.,Nichol, Gary S.,García-Domínguez, Andrés,Leach, Andrew G.,Lloyd-Jones, Guy C.
supporting information, p. 721 - 729 (2022/01/04)
The kinetics of quinuclidine displacement of BH3 from a wide range of Lewis base borane adducts have been measured. Parameterization of these rates has enabled the development of a nucleofugality scale (NFB), shown to quantify and predict the leaving group ability of a range of other Lewis bases. Additivity observed across a number of series R′3-nRnX (X = P, N; R′ = aryl, alkyl) has allowed the formulation of related substituent parameters (nfPB, nfAB), providing a means of calculating NFB values for a range of Lewis bases that extends far beyond those experimentally derived. The utility of the nucleofugality parameter is explored by the correlation of the substituent parameter nfPB with the hydrolyses rates of a series of alkyl and aryl MIDA boronates under neutral conditions. This has allowed the identification of MIDA boronates with heteroatoms proximal to the reacting center, showing unusual kinetic lability or stability to hydrolysis.
Intramolecular nucleophilic substitution of ω-haloalkylphosphine derivatives
Pawe?, Wo?nicki,Korzeniowska, Ewelina,Stankevic, Marek
, p. 10271 - 10296 (2018/02/27)
ω-Haloalkylphosphine derivatives undergo the intramolecular nucleophilic substitution reaction upon treatment with a strong base, yielding either cycloalkylphosphine derivatives or heterocyclic phosphine derivatives. The selectivity of the cyclization of
Mechanism of phosphine borane deprotection with amines: The effects of phosphine, solvent and amine on rate and efficiency
Lloyd-Jones, Guy C.,Taylor, Nicholas P.
supporting information, p. 5423 - 5428 (2015/03/30)
The kinetics of borane transfer from simple tertiary phosphine borane adducts to a wide range of amines have been determined. All data obtained, including second-order kinetics, lack of cross-over, and negative entropies of activation for reaction of triphenylphosphine borane with quinuclidine and triethylamine, are consistent with a direct (SN2-like) transfer process, rather than a dissociative (SN1-like) process. The identities of the amine, phosphine, and solvent all impact substantially on the rate (k) and equilibrium (K) of the transfer, which in some cases vary by many orders of magnitude. P-to-N transfer is more efficient with cyclic amines in apolar solvents due to reduced entropic costs and ground-state destabilisation. Taken as a whole, the data allow informed optimisation of the deprotection step from the stand-point of rate, or synthetic convenience. In all cases, both reactants should be present at high initial concentration to gain kinetic benefit from the bimolecularity of the process. Ultimately, the choice of amine is dictated by the identity of the phosphine borane complex. Aryl-rich phosphine boranes are sufficiently reactive to allow use of diethylamine or pyrrolidine as a volatile low polarity solvent and reactant, whereas more alkyl-rich phosphines benefit from the use of more reactive amines, such as 1,4-diaza[2.2.2]bicyclooctane (DABCO), in apolar solvents at higher temperatures. Efficient deprotection: Kinetic and thermodynamic data for amine-mediated deprotection of phosphine boranes under synthetically relevant conditions is consistent with an SN2-like rather than an SN1-like mechanism. The amine, solvent, and phosphine substituents all strongly influence the reaction efficiency (see scheme). The data allow an informed selection of optimal reaction conditions.
Synthesis and reactions of phosphine-boranes. Synthesis of new bidentate ligands with homochiral phosphine centers via optically pure phosphine-boranes
Imamoto, Tsuneo,Oshiki, Toshiyuki,Onozawa, Takashi,Kusumoto, Tetsuo,Sato, Kazuhiko
, p. 5244 - 5252 (2007/10/02)
Secondary and tertiary phosphine-boranes were synthesized in one-pot from phosphine oxides or substituted chlorophosphines without isolation of the intermediate phosphines. Phosphine-boranes having a methyl group were metalated with sec-butyllithium. The generated carbanions reacted with alkyl halides or carbonyl compounds to yield various phosphine-borane derivatives. The carbanions underwent copper(II)-promoted oxidative coupling without impairment of the borane functionality. Secondary phosphine-boranes reacted with alkyl halides, aldehydes, or α,β-unsaturated carbonyl compounds to give phosphine-borane derivatives having a functional group. The boranato group of phosphine-boranes was removed in a stereospecific manner with retention of configuration by treatment with a large excess of amine such as morpholine. A new route to bidentate ligands with homochiral phosphine centers has been explored by utilizing these characteristic reactivities of phosphine-boranes. Thus, optically pure (S,S)-1,2-bis(o-anisylphenylphosphino)ethane, (R,R)-1,2-bis(tert-butylphenyl-phosphino)ethane, and (S,S)-1,4-bis(o-anisylphenylphosphino)butane have been synthesized via phosphine-boranes.
