First reusable ligand-free palladium catalyzed C–P bond formation of aryl halides with trialkylphosphites in neat water

Abstract

A reusable ligand-free palladium catalyzed phosphonation of aryl iodides, bromides and chlorides with trialkylphosphites is described for the first time in neat water. The aryl phosphonates are obtained in good to excellent yields. The reaction can be also performed with Ni(II) with longer reaction time. The role of tetrabutylammonium bromide in this reaction as reducing agent for generation of Pd(0) at room temperature is also demonstrated. Pd(0)/TBAB was easily reused for three runs without decreasing the efficiency.

First direct access to 2-hydroxybenzophenones via nickel-catalyzed cross-coupling of 2-hydroxybenzaldehydes with aryl iodides

“…1). [20][21][22] According to the above results, a proposed mechanism for the aryl ketone formation is shown in Scheme 1. Step 1 involves an oxidative addition in which Ni(0) inserts into the aryl halide bond.…”

Palladium‐ Catalyzed C−P Bond Forming Reactions: An Overview

“…At first reusable ligand‐free Pd(0) catalytic method were reported for the efficient phosphonation of aryl halides (X=Cl, Br, I) and also for styryl bromide with different trialkylphosphites in neat water [45] . Good to excellent yields of aryl phosphonates were obtained with various functionalities (Scheme 13).…”

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

“…In continuation of our interest in the synthesis of phosphonate esters, [25] we now report am ethodf or activation of benzylic and non-benzylic alcohols as well as thiols to react with trialkylphosphites in refluxing acetonitrile for the efficient synthesis of the correspondingp hosphonate esters.…”