Synthesis of Aryl and Arylmethyl Phosphonates by Cross‐Coupling of Aryl or Arylmethyl Halides (X = I, Br and Cl) with Diisopropyl H‐Phosphonate

Abstract

An efficient and generally applicable protocol for the palladacycle‐catalysed arylation or K2CO3‐promoted arylmethylation of diisopropyl H‐phosphonate has been developed. The remarkable features of the palladacycle‐catalysed arylation reaction include wide substrate scope (aryl iodides, bromides and chlorides), significant shortening of the reaction time (2 or 3 h) and a low catalyst loading of 1 mol‐%. Note that with the base K2CO3 as promoter, arylmethylation could be achieved without any palladium catalyst. Moreover, the first example of a palladium‐catalysed phosphonation of inactive electron‐rich aryl chlorides with tBuOK as the base has been realized. This result could be considered an important improvement and complement to earlier work of Montchamp and Han, whose catalytic systems are typically compatible with electron‐deficient and electron‐neutral aryl chlorides.

Recent Advances in H-Phosphonate Chemistry. Part 2. Synthesis of C-Phosphonate Derivatives

“…Wu, Yang, et al [113] recently developed a new catalytic system based on cyclopalladated ferrocenylimines (cpf, Fig. 3) which efficiently performed synthesis of aryl-and benzylphosphonates.…”

Triphenylphosphine/2,3‐Dichloro‐5,6‐dicyanobenzoquinone (PPh3/DDQ) System for Conversion of Alcohols and Thiols into Trialkyl Phosphonates

“…[10] After that, Xu et al reported the use of hydrogen diisopropylp hosphonate in conjunction with benzyl bromideo rbenzyl chloride to produce the desired phosphonate derivatives. [11] In addition, the Stawinski group has obtained dialkyl benzylphosphonates from benzylc hlorides in the presenceo fap alladium catalyst under an inert atmosphere in refluxing THF.…”

“…Furthermore, transition metal catalystsa re also required in the reaction of benzyl chloride derivatives. [11,12,15] In this regard, finding new reagents in which the benzylm oiety has attached to ab etter living group is of great interest. Consequently,a lcohols have attracted ag reat deal of attentioni nr ecent years because the hydroxy group is easily converted into ab etter leaving group.…”

“…[13] Performing the reaction under microwave irradiation has also been appliedf or preparation of the desired products from benzyl bromides. [14] In order to activate the benzylh alidesf or the reaction, high reactiont emperature (100-180 8C) [10,11,15] were required for most of the above reported protocols in which phosphonate esters derivatives were synthesized. Furthermore, transition metal catalystsa re also required in the reaction of benzyl chloride derivatives.…”

Designing of Ferromagnetic 3D Hierarchical Core‐Shell Fe3O4@NiO/Co3O4 Microspheres Derived from a MOF Precursor: As an Efficient Catalyst for C‐P Cross Coupling Reaction

“…Transition metal catalysts such as Pd, Pt, Rh, Mo, Cu and Ni have gained enormous attention as a powerful and straightforward for the direct phosphorylation reaction. Undoubtedly, these catalytic systems represent a valuable synthetic route for the preparation of organophosphorus compounds, nevertheless, some of them still have limitations and suffer from some drawbacks, including hazardous organic solvents, expensive noble metal catalysts, ancillary ligands, unrecyclable metal catalysts and microwave irradiation . Hence, from a chemical industry point of view, the emergence of conceptually‐new, direct, efficient and practical procedure for the C−P bond forming reaction is criteria.…”