92439-07-1Relevant academic research and scientific papers
Hydrogen-bond-assisted transition-metal-free catalytic transformation of amides to esters
Huang, Changyu,Li, Jinpeng,Wang, Jiaquan,Zheng, Qingshu,Li, Zhenhua,Tu, Tao
, p. 66 - 71 (2020/11/18)
The amide C-N cleavage has drawn a broad interest in synthetic chemistry, biological process and pharmaceutical industry. Transition-metal, luxury ligand or excess base were always vital to the transformation. Here, we developed a transition-metal-free hydrogen-bond-assisted esterification of amides with only catalytic amount of base. The proposed crucial role of hydrogen bonding for assisting esterification was supported by control experiments, density functional theory (DFT) calculations and kinetic studies. Besides broad substrate scopes and excellent functional groups tolerance, this base-catalyzed protocol complements the conventional transition-metal-catalyzed esterification of amides and provides a new pathway to catalytic cleavage of amide C-N bonds for organic synthesis and pharmaceutical industry. [Figure not available: see fulltext.]
Fluoride anion-initiated bis-trifluoromethylation of phenyl aromatic carboxylates with (trifluoromethyl)trimethylsilane
Takahashi, Kenjiro,Ano, Yusuke,Chatani, Naoto
supporting information, p. 11661 - 11664 (2020/10/19)
The fluoride anion-initiated reaction of phenyl aromatic carboxylates with (trifluoromethyl)trimethylsilane (Me3SiCF3) that results in the formation of O-silyl-protected 2-aryl-1,1,1,3,3,3-hexafluoroisopropanols is reported. A phenoxide anion, generated during the trifluoromethylation of the phenyl carboxylate, also activates the Me3SiCF3, which permits a catalytic amount of the fluoride anion source to be used. Various functional groups, which can be used for further elaboration, are tolerated in the reaction.
Switchable Selectivity in the Pd-Catalyzed Alkylative Cross-Coupling of Esters
Masson-Makdissi, Jeanne,Vandavasi, Jaya Kishore,Newman, Stephen G.
supporting information, p. 4094 - 4098 (2018/07/15)
The Pd-catalyzed cross-coupling of phenyl esters and alkyl boranes is disclosed. Two reaction modes are rendered accessible in a selective fashion by interchange of the catalyst. With a Pd-NHC system, alkyl ketones can be prepared in good yields via a Suzuki-Miyaura reaction proceeding by activation of the C(acyl)-O bond. Use of a Pd-dcype catalyst enables alkylated arenes to be synthesized by a modified pathway with extrusion of CO. Applications of this divergent coupling strategy and the origin of the switchable selectivity are discussed.
Condensation Product of Salicylaldehyde and 2-Bromo-2'-hydroxyacetophenone: Revision of Structure
Joshi, U. K.,Paradkar, M. V.
, p. 378 - 379 (2007/10/02)
Reaction between salicylaldehyde and 2-bromo-2'-hydroxyacetophenone (1) gives 2-(2-hydroxybenzylidene)coumaran-3-one (5) rather than 2-(2-hydroxybenzoyl)benzofuran (2) as reported in a patented literature.
Synthesis of 4-(2-Benzofuranyl)coumarins
Deshpande, A. R.,Joshi, U. K.,Paradkar, M. V.
, p. 524 - 526 (2007/10/02)
4-(2-Benzofuranyl)coumarins (3) have been synthesized by two routes, one involving Pechmann condensation of benzofuranpropionic acid-β-oxo-ethyl ester with phenols and the other involving Wittig reaction on 2-(2-hydroxybenzoyl)benzofuran using Ph3P=CHCOOE
