52787-16-3Relevant academic research and scientific papers
Hydration of Aliphatic Nitriles Catalyzed by an Osmium Polyhydride: Evidence for an Alternative Mechanism
Babón, Juan C.,Esteruelas, Miguel A.,López, Ana M.,O?ate, Enrique
, p. 7284 - 7296 (2021/05/29)
The hexahydride OsH6(PiPr3)2 competently catalyzes the hydration of aliphatic nitriles to amides. The main metal species under the catalytic conditions are the trihydride osmium(IV) amidate derivatives OsH3{κ2-N,O-[HNC(O)R]}(PiPr3)2, which have been isolated and fully characterized for R = iPr and tBu. The rate of hydration is proportional to the concentrations of the catalyst precursor, nitrile, and water. When these experimental findings and density functional theory calculations are combined, the mechanism of catalysis has been established. Complexes OsH3{κ2-N,O-[HNC(O)R]}(PiPr3)2 dissociate the carbonyl group of the chelate to afford κ1-N-amidate derivatives, which coordinate the nitrile. The subsequent attack of an external water molecule to both the C(sp) atom of the nitrile and the N atom of the amidate affords the amide and regenerates the κ1-N-amidate catalysts. The attack is concerted and takes place through a cyclic six-membered transition state, which involves Cnitrile···O-H···Namidate interactions. Before the attack, the free carbonyl group of the κ1-N-amidate ligand fixes the water molecule in the vicinity of the C(sp) atom of the nitrile.
A Metallaphotoredox Strategy for the Cross-Electrophile Coupling of α-Chloro Carbonyls with Aryl Halides
Chen, Tiffany Q.,MacMillan, David W. C.
supporting information, p. 14584 - 14588 (2019/09/17)
Here, we demonstrate that a metallaphotoredox-catalyzed cross-electrophile coupling mechanism provides a unified method for the α-arylation of diverse activated alkyl chlorides, including α-chloroketones, α-chloroesters, α-chloroamides, α-chlorocarboxylic acids, and benzylic chlorides. This strategy, which is effective for a wide variety of aryl bromide coupling partners, is predicated upon a halogen atom abstraction/nickel radical-capture mechanism that is generically successful across an extensive range of carbonyl substrates. The construction and use of arylacetic acid products have further enabled two-step protocols for the delivery of valuable building blocks for medicinal chemistry, such as aryldifluoromethyl and diarylmethane motifs.
A facile one-carbon homologation of aryl aldehydes to amides.
Shen, Wang,Kunzer, Aaron
, p. 1315 - 1317 (2007/10/03)
The easily accessible 2-aryl-1,1-dibromo-1-alkenes can be converted to amides under unusually mild conditions in good to excellent yields. Both electron-donating and electron-withdrawing substitutions on the aromatic rings are tolerated, and the reaction works well with hindered alkylamines. This simple homologation could find broad applications. [reaction: see text]
