Palladium‐catalysed PC bond forming reactions between diphenylphosphine and ortho‐substituted aryl bromides

Abstract

The use of palladium catalysts derived from 1,1 -bis-diisopropylphosphino-ferrocene and a microwave heating source allows the coupling of a range of ortho-substituted aryl bromides to diphenylphosphine derivatives to proceed in good yield in under 30 min. Optimization studies reveal that the combination of diphenylphosphine and DABCO is superior to more basic phosphide nucleophiles such as Ph 2 PK or Ph 2 PMgBr. High yields are only observed when moderately bulky electron rich diphosphines are used as ligands. The differences between P-C coupling and other cross-coupling reactions are discussed in the light of the reactivity observed. Studies aimed at producing industrially important 1,2-bis-phosphino-benzene ligands are also described.

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

“…They did not discuss diarylphosphine coupling which was well described by Clarke et al [40] . In this particular work, Pd‐catalyzed C−P bond forming reactions between ortho ‐substituted aryl bromides and diphenylphosphine derivatives were discussed.…”

Palladium-catalyzed cross-coupling of various phosphorus pronucleophiles with chloropyrazines: synthesis of novel Am(iii)-selective extractants

“…However, kinetic and computational studies on the coupling of aryl halides with dialkyl phosphites and secondary phosphines have been published. 20 Kohler et al 21 synthesized stable arylpalladium intermediates containing a dialkylphosphonate fragment. This study on the ligand influence on the arylpalladium complex stability revealed that the reductive elimination of the corresponding arylphosphonate happens much faster, almost instantaneously, in the case of palladium complexes with diphosphine ligands compared to those with bipyridyls, for example.…”

“…of diphenylphosphine (3) in the presence of 1 equiv. of DBU and 1 mol% of Pd(dppf )Cl 2 in refluxing acetonitrile overnight, followed by oxidation of the diphenylphosphino group with hydrogen peroxide in acetone, afforded 6-(diphenylphosphoryl)-N,N-dioctylpyrazine-2-carboxamide (20) in 75% yield (Scheme 5). In the 1…”

Palladium-Catalyzed C–P Cross-Coupling between (Het)aryl Halides and Secondary Phosphine Oxides

“…Tertiary phosphines in turn can be obtained by nucleophilic aromatic substitution of halide by alkali metal phosphides, 6,[28][29][30][31] as well as by alkylation of P-H phosphines, 32 and from the reaction of Grignard reagents with PCl 3 ; 33 more recent studies have utilized transitionmetal-catalyzed transformations. 23,[34][35][36] A transition-metalcatalyzed cross-coupling reaction between organic halides and phosphorus-containing compounds is the most promising method for obtaining aromatic TPOs. The first example of such a transformation, reported by Hirao and coworkers, 37 was the reaction between sp 2 -halides and P-H phosphites; the scope has now been expanded to other phosphorus-containing compounds and organic electrophiles, and improved reaction conditions are also available; progress in the field has been recently reviewed.…”

“…38 It is not necessary to use halides as the initial aromatic precursor: several studies have shown the formation of an Ar-P(O) bond from hydroxyl compounds (Ar-OH), 39 sulfur derivatives (Ar-SO n Me, n = 0, 1, 2) 40 and esters (Ar-COOR). 41 Cross-coupling chemistry can be exploited in two ways: reaction between halides and secondary phosphines with subsequent oxidation, 36 or direct reaction between halides and secondary phosphine oxides (SPOs). [23][24][25][26][27] Recently, we reported 42 the first example of a palladium-catalyzed reaction between pyridine-type dichlorides and tert-butyl(phenyl)phosphine/diphenylphosphine oxides.…”