A high‐efficient method for the amidation of carboxylic acids promoted by triphenylphosphine oxide and oxalyl chloride

Abstract

A effective amidation reaction of carboxylic acids with various amines promoted by triphenylphosphine oxide and oxalyl chloride under mild and neutral conditions has been developed. The feature of this procedure was the using and recycling of triphenylphosphine oxide at room temperature in 0.5 h. Furthermore a plausible mechanism also be deduced with the help of 31P NMR spectroscopy.

Driving Recursive Dehydration by PIII/PV Catalysis: Annulation of Amines and Carboxylic Acids by Sequential C–N and C–C Bond Formation

“…Indeed, halophosphonium intermediates have been invoked by Rutjes and van Delft 5 and Mecinović 16 in the context of P III /P V -catalyzed Appel halogenation and N -acylation reactions, respectively. 17 In view of the fact that phosphonium reagents have been described as having “virtually ideal properties as selective oxygen extractors for net dehydration reactions,” 18,19 the potential to achieve recursive dehydrations in an autotandem catalytic manner via a net redox-neutral mode of P III /P V catalysis could be expected to present new opportunities for serial bond formation.…”

A novel and highly efficient esterification process using triphenylphosphine oxide with oxalyl chloride

“…Firstly, the solution after adding TPPO ( δ = 29.26 ppm) [ 46 ] with (COCl) 2 showed a strong singlet at 65.11 ppm ( figure 1 , I) ( δ = 65.5 ppm [ 51 ]), indicating the formation of intermediate 1. Secondly, after adding benzoic acid, a new singlet was formed at δ = 44.43 ppm ( figure 1 , II) [ 46 ], which we hypothesized was due to the formation of an acyl phosphonium salt 2. To exclude the effect of a base, we tested the mixture of TPPO, CH 3 CN with benzoic acid and did not find the analogous singlet; furthermore, we could only see a singlet at 29 ppm.…”

Oxalyl Chloride: A Versatile Reagent in Organic Transformations

“…Oxalyl chloride/TPPO system was applied as a high‐efficiency coupling reagent for the synthesis of esters 155 and amides 160 with excellent yields via esterification of alcohols 154 with carboxylic acids 23 or acylation of amines 152 with carboxylic acids 23 at ambient temperature in short reaction time under mild and neutral conditions, respectively (Scheme ). Considerably, TPPO was recycled since it is a catalyst and CO, CO 2 , and HCl were wasted at the end of the reaction.…”