51310-27-1Relevant articles and documents
Copper-Catalyzed C(sp3)?H Amidation: Sterically Driven Primary and Secondary C?H Site-Selectivity
Bakhoda, Abolghasem (Gus),Jiang, Quan,Badiei, Yosra M.,Bertke, Jeffery A.,Cundari, Thomas R.,Warren, Timothy H.
, p. 3421 - 3425 (2019/02/14)
Undirected C(sp3)?H functionalization reactions often follow site-selectivity patterns that mirror the corresponding C?H bond dissociation energies (BDEs). This often results in the functionalization of weaker tertiary C?H bonds in the presence of stronger secondary and primary bonds. An important, contemporary challenge is the development of catalyst systems capable of selectively functionalizing stronger primary and secondary C?H bonds over tertiary and benzylic C?H sites. Herein, we report a Cu catalyst that exhibits a high degree of primary and secondary over tertiary C?H bond selectivity in the amidation of linear and cyclic hydrocarbons with aroyl azides ArC(O)N3. Mechanistic and DFT studies indicate that C?H amidation involves H-atom abstraction from R-H substrates by nitrene intermediates [Cu](κ2-N,O-NC(O)Ar) to provide carbon-based radicals R. and copper(II)amide intermediates [CuII]-NHC(O)Ar that subsequently capture radicals R. to form products R-NHC(O)Ar. These studies reveal important catalyst features required to achieve primary and secondary C?H amidation selectivity in the absence of directing groups.
Evolutions differentes de radicaux anions formes par voie chimique ou electrochimique
Archier-Jay, Danielle,Besbes, Neji,Laurent, Andre,Laurent, Eliane,Lesniak, Stanislaw,Tardivel, Robert
, p. 537 - 543 (2007/10/02)
Chemical and electrochemical reductions of N-aroylaziridines 1 are described and compared.The first step is a single electron transfer (1 +e -> 1-. -> 1'-.).But compounds obtained from 1'-. are depending on the method used way followed: chemical reduction of N-cinnamoylaziridine 1e provides pyrrolidone 10e; but oxazoline 11e is available by electrochemical reduction of the same starting material 1e.Counter ion seems responsible of these different results.In agreement with this hypothesis, it is shown that pyrrolidone 10e is obtained from 1j only in presence of a counter ion.
