66067-44-5Relevant articles and documents
Suzuki-Miyaura cross-coupling of esters by selective O-C(O) cleavage mediated by air- And moisture-stable [Pd(NHC)(μ-Cl)Cl]2precatalysts: Catalyst evaluation and mechanism
Cavallo, Luigi,Nolan, Steven P.,Poater, Albert,Szostak, Michal,Yang, Shiyi,Zhou, Tongliang
, p. 3189 - 3197 (2021/05/25)
The cross-coupling of aryl esters has emerged as a powerful platform for the functionalization of otherwise inert acyl C-O bonds in chemical synthesis and catalysis. Herein, we report a combined experimental and computational study on the acyl Suzuki-Miyaura cross-coupling of aryl esters mediated by well-defined, air- and moisture-stable Pd(ii)-NHC precatalysts [Pd(NHC)(μ-Cl)Cl]2. We present a comprehensive evaluation of [Pd(NHC)(μ-Cl)Cl]2 precatalysts and compare them with the present state-of-the-art [(Pd(NHC)allyl] precatalysts bearing allyl-type throw-away ligands. Most importantly, the study reveals [Pd(NHC)(μ-Cl)Cl]2 as the most reactive precatalysts discovered to date in this reactivity manifold. The unique synthetic utility of this unconventional O-C(O) cross-coupling is highlighted in the late-stage functionalization of pharmaceuticals and sequential chemoselective cross-coupling, providing access to valuable ketone products by a catalytic mechanism involving Pd insertion into the aryl ester bond. Furthermore, we present a comprehensive study of the catalytic cycle by DFT methods. Considering the clear advantages of [Pd(NHC)(μ-Cl)Cl]2 precatalysts on several levels, including facile one-pot synthesis, superior atom-economic profile to all other Pd(ii)-NHC catalysts, and versatile reactivity, these should be considered as the 'first-choice' catalysts for all routine applications in ester O-C(O) bond activation.
FeCl3-catalyzed oxidative decarboxylation of aryl/heteroaryl acetic acids: Preparation of selected API impurities
Gangadurai, Chinnakuzhanthai,Illa, Giri Teja,Reddy, D. Srinivasa
, p. 8459 - 8466 (2020/11/05)
There is an ever-increasing demand for impurity compounds for use in impurity profiling as regulatory agencies seek information during registration. Herein, we report the FeCl3-catalyzed oxidative decarboxylation of aryl- and heteroaryl acetic acids to the corresponding carbonyl compounds. A variety of useful aldehydes and ketones were prepared in a simple one-pot transformation by employing an environmentally benign, low-cost, and readily available iron salt. The utility of this method has been demonstrated by preparing five valuable API impurities including a multi-gram-scale synthesis of ketorolac impurity B for the first time. This journal is
Photoredox-Catalyzed Decarboxylative Oxidation of Arylacetic Acids
Sakakibara, Yota,Cooper, Phillippa,Murakami, Kei,Itami, Kenichiro
supporting information, p. 2410 - 2413 (2018/06/04)
A photoredox-catalyzed decarboxylative oxidation of arylacetic acids, which are privileged scaffolds in pharmaceuticals, is reported herein. The established method is operationally simple and a variety of substrates are applicable, providing rapid access to dehomologated bioisosteres of common pharmaceuticals.
