Lewis-acid-catalyzed phosphorylation of alcohols

An efficient method has been developed for reacting dialkyl H-phosphonates or diarylphosphine oxides with alcohols for constructing C-P bonds. This reaction was catalyzed by Lewis acid and involved nucleophilic substitution. A series of diphenylphosphonates and diphenylphosphine oxides were obtained, from the phosphorylation of alcohols, with good-to-excellent yields.

Simple Synthesis of Dimethyl Nitrobenzhydrylphosphonates and Heteroarylnitroarylacetonitriles via Vicarious Nucleophilic Substitution (VNS) Reaction

Acetals of dimethyl phenyl- and heteroaryl-α-hydroxymethanephosphonates were deprotonated to generate carbanions, which enter the vicarious nucleophilic substitution (VNS) of hydrogen in aromatic nitro compounds to form 4-nitrobenzhydrylphosphonates and α-heteroaryl-4-nitrobenzylphosphonates. Similarly acetals of cyano­hydrins of heteroaromatic aldehydes (furfural and 2-formylthiophene) react to form heteroaryl 4-nitroarylacetonitriles. The anion of the hemiacetal of acetaldehyde is an efficient leaving group in the base-induced β-elimination step – the crucial step in the VNS reaction. The reaction selectively occurred at the para-position to the nitro group.

Synthetic Methodologies for Perfluoroaryl-Substituted (Diaryl)methylphosphonates, -Phosphinates via SNAr Reaction

The new synthetic methodologies for perfluoroaryl-substituted (diaryl)methylphosphonates, -phosphinates via nucleophilic aromatic substitution (S_NAr) were developed. Benzylphosphonate and α-fluorobenzylphosphonate reacted with a wide variety of perfluoroarenes via S_NAr reaction. The reaction took place quickly and gave perfluoroarylated phosphonates in high yields. Highly diastereoselective S_NAr reaction with binaphthyl-based chiral phosphinates was further carried out.

Synthesis and Reactions of α-Hydroxyphosphonates

This review summarizes the main synthetic routes towards α-hydroxyphosphonates that are known as enzyme inhibitors, herbicides and antioxidants, moreover, a number of representatives express antibacterial or antifungal effect. Special attention is devoted to green chemical aspects. α-Hydroxyphosphonates are also versatile intermediates for other valuable derivatives. O-Alkylation and O-acylation are typical reactions to afford α-alkoxy-, or α-acyloxyphosphonates, respectively. The oxidation of hydroxyphosphonates leads to ketophosphonates. The hydroxy function at the α carbon atom of hydroxyphosphonates may be replaced by a halogen atom. α-Aminophosphonates formed in the nucleophilic substitution reaction of α-hydroxyphosphonates with primary or secondary amines are also potentially bioactive compounds. Another typical reaction is the base-catalyzed rearrangement of α-hydroxy-phosphonates to phosphates. Hydrolysis of the ester function of hydroxyphosphonates leads to the corresponding phosphonic acids.

Palladium-Catalyzed Benzylic Phosphorylation of Diarylmethyl Carbonates

A palladium-catalyzed benzylic substitution of tert-butyl diarylmethyl carbonates with a pinacol-derived H-phosphonate proceeds to deliver the corresponding benzylic phosphorylated products in good yields. Moreover, the asymmetric synthesis is possible via a Pd/( R_p, R'_p)-( S)-Mandyphos-catalyzed kinetic resolution-DYKAT (dynamic kinetic asymmetric transformation) sequence, and optically active α-chiral diarylmethylphosphonates are obtained with synthetically useful yields and enantiomeric ratios (up to 50% and 92:8 er).

Straightforward Synthesis of Bifunctional Phosphorus Phenols via Phosphination of In Situ Generated o-Quinone Methides

An efficient and practical approach towards bifunctional phosphorus phenols has been developed through a reaction of diphenylphosphine oxide and the o-quinone methides in situ generated from 2-tosylalkyl phenols under basic conditions. This protocol features simple experimental procedures under mild conditions and is easily scaled up. With this method, a variety of diarylmethyl phosphine oxides can be produced with up to 92% yield.

N-Heterocyclic carbene catalysed 1,6-hydrophosphonylation of p-quinone methides and fuchsones: an atom economical route to unsymmetrical diaryl- and triarylmethyl phosphonates

A direct method for the synthesis of diaryl- and triarylmethyl phosphonates through 1,6-hydrophosphonylation ofp-quinone methides and fuchsones using NHC as a Brønsted base catalyst is described.

An easy access to α-aryl substituted γ-ketophosphonates: Lewis acid mediated reactions of 1,3-diketones with α-hydroxyphosphonates and tandem regioselective C-C bond cleavage

A range of α-aryl substituted γ-ketophosphonates is synthesised by Lewis acid mediated reactions of 1,3-diketones and easily accessible, inexpensive benzylic α-hydroxyphosphonates in an operationally simple method under solvent-free conditions without exclusion of air/moisture. A regioselective C-C bond cleavage for 1,3-diketones in a tandem fashion has also been demonstrated. Synthesis of a γ-ketophosphonate with phenol functionality at the α-position (structural analogue of raspberry ketone, a natural product) has also been presented.

Palladium-catalyzed α-arylation of benzylic phosphonates

A new synthetic route to access diarylmethyl phosphonates is presented. The transformation enables the introduction of aromatic groups on benzylic phosphonates via a deprotonative cross-coupling process (DCCP). The Pd(OAc)2/CataCXium A-based catalyst afforded a reaction between benzyl diisopropyl phosphonate derivatives and aryl bromides in good to excellent isolated yields (64-92%).