Low-Coordinated Organophosphorus Compounds Research Articles

Chemistry of Several Sterically Bulky Molecules with P=P, P=C, and C≡P Bond.

Several sterically protected, low-coordinate organophosphorus compounds with P=P, P=C, and C≡P bond are described in this study. Molecules such as diphosphenes, phosphaalkenes, 1-phosphaallenes, 1,3-diphosphaallenes, 3,4-diphosphinidenecyclobutenes, and phosphaalkynes are stabilized with an extremely bulky 2,4,6-tri-t-butylphenyl (Mes*) group. The synthesis, structures, physical, and chemical properties of these molecules are discussed, together with some successful applications in catalytic organic reactions.

Low coordinate phosphorus compounds for 40 years in memory of the late professor François Mathey, Ecole Polytechnique

Sterically protected low-coordinate organophosphorus compounds such as diphosphenes, phosphaalkenes, 1,3-diphosphaallenes, 1-phosphaallenes, phosphaalkynes, and 3,4-diphosphinidenecyclobutenes are described, which are stabilized with an extremely bulky 2,4,6-tri-t-butylphenyl (Mes*) group. The structures, physical and chemical properties are highly interesting, because they are unusual phosphorus compounds.

Stereochemical features of low-coordinate organophosphorus compounds

Various kinds of sterically protected low-coordinate phosphorus compounds with Mes* (2,4,6-tri-tert-butylphenyl) group such as diphosphenes, 1-phosphaethenes, 1-phosphaallenes, 1,3-diphosphaallenes, and 3,4-diphosphinidenecyclobutenes are discussed in terms of stereochemistry including E/Z photo-isomerization around the P = P or P = C bond and R/S identification of rotational isomers around the crowded P–C bonds. (π-Allyl)palladium complexes ligated with 3,4-diphosphinidenecyclobutenes are useful in catalytic organic reactions such as the Tsuji-Trost reaction and the mechanism is proposed to interpret products.

Low-coordinate organophosphorus compounds: some stereochemical considerations

Abstract Utilizing 2,4,6-tri-tert-butylphenyl as a sterically demanding group (abbreviated as Mes*), we have been successful in isolation, characterization, physical and chemical property investigation of low-coordinate organophosphorus compounds such as those carrying P=P and P=C bonds. Diphosphene, 1-phosphaethene, 1,3-diphosphaallene, 1-phosphaallene, and 3,4-diphosphinidenecyclobutenes are discussed in terms of stereochemistry including E/Z isomerization around P=P or P=C bond and R/S resolution of rotational isomers around crowded P–C bonds with chiral HPLC column. (π-Allyl)palladium complexes ligated with 3,4-diphosphinidenecyclobutene are useful in such catalytic organic reactions as the Tsuji-Trost reaction by which from a chiral s-alcohol, the corresponding chiral amine is obtained with retention of chirality suggesting double inversion process.

A concise review of low coordinated organophosphorus compounds

Organophosphorus chemistry is organized around σ 3 and σ 4 phosphorus compounds and their derivatives. For a long time, this represented the core of phosphorus chemistry and, still today, the bulk of the work on phosphorus concerns this domain. Starting in the 1960s, a new realm of P-chemistry started to emerge. It concerns σ 1 and σ 2 phosphorus compounds. The aim of this concise review is to summarize the main advances in this new field.

Recent developments in the chemistry of low-coordinated organophosphorus compounds

Abstract Sterically protected organophosphorus compounds are described, involving diphosphenes, phosphaethenes, diphosphinidenecyclobutenes (DPCBs), phosphaalkynes, phosphaquinones, diphosphathienoquinones, and so on of coordination number 2 or 1. Application of the DPCBs as well as phosphinophosphaethenes as a ligand of transition-metal catalysts for several organic coupling reactions has been investigated.

Low‐Coordinated Organophosphorus Compounds

AbstractFor Abstract see ChemInform Abstract in Full Text.

Low-Coordinated Organophosphorus Compounds

Low-coordinate organophosphorus compounds can be prepared by steric protection. They are diphosphenes, phosphaethenes, phosphaallenes, phosphabutatrienes, phosphaalkynes, and so on, of coordination number 2 and 1 .

Protecting groups for stabilization of inter-element linkages

Various kinds of protective groups for stabilization of low-coordinated organophosphorus compounds are reviewed, in terms of steric effect and electronic effect, with some typical examples involving diphosphenes, phosphaalkenes, phosphaallenes, phosphabenzoquinones, diphosphinidenecyclobutenes, thioxophosphines, selenoxophosphines, dithioxophosphoranes, diselenoxophosphoranes, and phosphaalkynes.

Coordination chemistry of some low-coordinate organophosphorus compounds

Abstract

Reactions of Sterically Protected 1-Halo- and 1-Pseudohalo-2-Phosphaethenyl-Lithiums

Phosphorus analogs of alkylidenecarbenoid, Ar-P=C(X)Li, where X equals halogen or pseudohalogen atom, such as C1, Br, or SPh, have been generated by use of the 2,4,6-tri-t-butylphenyl group (abbreviated to Ar in the Scheme) as a protecting group for low coordinated organophosphorus compounds. The reaction with methyl iodide and with some aldehydes or ketones, at low temperature, gave the corresponding alkylation products[l]. The reaction with copper salts gave 1,4-diphosphabutadiene (1) or 1,4-diphosphabutatriene (2), depending upon the substituent X[2,3], as well as reaction conditions, such as reaction tenlperature and time, solvent, presence or absence of oxygen. Upon warming the phosphaethenyllithiun1s, thus generated, the chloro derivative of E-configuration gave a phosphaalkyne (3) via [1,2]-aromatic migration[4], whereas the bromo derivative of Z-configuration gave a l-phospha-3,4-dihydronaphthalene derivative (4), that is a formal C-H insertion product of a phosphinidenecarbene intermediate[5].

Coordination Chemistry of Some Low Coordinate Organophosphorus Compounds of Coordination Number 2

Abstract The structures of transition metal complexes with low coordinate organophosphorus compounds are described; these compounds involve diphosphenes, phosphaethenes, phosphaallenes, phosphabutatrienes, and so on of coordination number 2. They are discussed in terms of X-ray crystallographic analysis and 31P NMR analysis.

Competitive Addition and Cycloaddition of Low Coordinated Organophosphorus Compounds to Alkoxy- and Aminoalkynes

Competitive Addition and Cycloaddition of Low Coordinated Organophosphorus Compounds to Alkoxy- and Aminoalkynes

Competitive Addition and Cycloaddition of Low Coordinated Organophosphorus Compounds To Alkoxy- and Aminoalkynes.

Abstract Reactions of two- and three coordinated organophosphorus compounds with nucleophilic alkynes can proceed as competitive addition, [2+1]-, and [2+2]- cycloaddition reactions. Ring-chain tautomerism for phosphirenes and isomeric alkenylphosphines has been observed.

X-Ray Analysis of a Captodative Diphosphene, 1-(N-Mesityl-9-fluorenylamino)-2-[2,4,6-tris(trifluoromethyl)phenyl]diphosphene

Abstract The N-mesityl-9-fluorenylamino group was utilized as an electron-donating new sterically protecting group for stabilizing low coordinate organophosphorus compounds. A push–pull substituent effect on the P–P double bond was demonstrated by the X-ray analysis of a captodative diphosphene, 1-(N-mesityl-9-fluorenylamino)-2-[2,4,6-tris(trifluoromethyl)phenyl]diphosphene.