62128-31-8Relevant articles and documents
Selective PdII-Catalyzed Acylation of Pyrrole with Aldehydes. Application to the Synthesis of Celastramycin Analogues and Tolmetin
Santiago, Carlos,Rubio, Ibon,Sotomayor, Nuria,Lete, Esther
, p. 4284 - 4295 (2020/05/25)
The PdII-catalyzed C-2 acylation of pyrrole with aldehydes in the presence of TBHP as oxidant has been studied for the synthesis of di(hetero)aryl ketones. The use of 2-pyrimidine as directing group leads to 2-acylpyrroles in moderate to good yields, although 2,5-diacylpyrroles are obtained as by products. This side-reaction could be avoided using 3-methy-2-pyridine as directing group, obtaining selectively 2-acylpyrroles. The reaction has been extended to a series of aromatic and heteroaromatic aldehydes, obtaining the best results with electron rich aromatic aldehydes. The methodology has been applied in the synthesis of pyrrolomycin alkaloid Celastramycin analogues and for an improved synthesis of Tolmetin, a nonsteroidal anti-inflammatory drug.
A general approach to intermolecular carbonylation of arene C-H bonds to ketones through catalytic aroyl triflate formation
Kinney, R. Garrison,Tjutrins, Jevgenijs,Torres, Gerardo M.,Liu, Nina Jiabao,Kulkarni, Omkar,Arndtsen, Bruce A.
, p. 193 - 199 (2018/02/06)
The development of metal-catalysed methods to functionalize inert C-H bonds has become a dominant research theme in the past decade as an approach to efficient synthesis. However, the incorporation of carbon monoxide into such reactions to form valuable ketones has to date proved a challenge, despite its potential as a straightforward and green alternative to Friedel-Crafts reactions. Here we describe a new approach to palladium-catalysed C-H bond functionalization in which carbon monoxide is used to drive the generation of high-energy electrophiles. This offers a method to couple the useful features of metal-catalysed C-H functionalization (stable and available reagents) and electrophilic acylations (broad scope and selectivity), and synthesize ketones simply from aryl iodides, CO and arenes. Notably, the reaction proceeds in an intermolecular fashion, without directing groups and at very low palladium-catalyst loadings. Mechanistic studies show that the reaction proceeds through the catalytic build-up of potent aroyl triflate electrophiles.
Acylation of pyrroles and their free (N-H)-derivatives via palladium-catalyzed carbopalladation of nitriles
Jafarpour, Farnaz,Hazrati, Hamideh,Darvishmolla, Masoumeh
supporting information, p. 3784 - 3788 (2015/02/19)
An efficient regioselective synthesis of 2-acylpyrroles via palladium-catalyzed addition of pyrroles with benzonitriles and subsequent hydrolysis is developed. The direct acylation reaction of protected as well as (NH)-free pyrroles proceeded smoothly to
