1351765-81-5Relevant articles and documents
Chromium(III)-Catalyzed C(sp2)-H Alkynylation, Allylation, and Naphthalenation of Secondary Amides with Trimethylaluminum as Base
Chen, Mengqing,Doba, Takahiro,Ilies, Laurean,Nakamura, Eiichi,Razumkov, Hlib,Sato, Takenari,Shang, Rui
supporting information, p. 4883 - 4891 (2020/04/01)
Among base metals used for C-H activation reactions, chromium(III) is rather unexplored despite its natural abundance and low toxicity. We report herein chromium(III)-catalyzed C(sp2)-H functionalization of an ortho-position of aromatic and α,β-unsaturated secondary amides using readily available AlMe3 as a base and using bromoalkynes, allyl bromide, and 1,4-dihydro-1,4-epoxynaphthalene as electrophiles. This redox-neutral reaction taking place at 70-90 °C, requires as low as 1-2 mol % of CrCl3 or Cr(acac)3 as a catalyst without any added ligand, and tolerates functional groups such as aryl iodide, boronate, and thiophene groups. Stoichiometric and kinetics studies as well as kinetic isotope effects suggest that the catalytic cycle consists of a series of thermally stable but reactive intermediates bearing two molecules of the amide substrate on one chromium atom and also that one of these chromate(III) complexes takes part in the alkynylation, allylation, and naphthalenation reactions. The proposed mechanism accounts for the effective suppression of methyl group delivery from AlMe3 for ortho-C-H methylation.
Anti-Markovnikov Hydroazidation of Alkenes by Visible-Light Photoredox Catalysis
Wang, Juan-Juan,Yu, Wei
supporting information, p. 3510 - 3514 (2019/02/19)
The anti-Markovnikov hydroazidation of alkenes has been accomplished under visible-light irradiation by using [Ir(dF(CF3)ppy)2(dtbbpy)]PF6 as the photocatalyst and trimethylsilyl azide as the azidating agent. The reactions were greatly facilitated by water, the beneficial effect of which can be attributed to its participation in the reaction as the hydrogen donor, as indicated by deuterium isotope experiments. The reactions proceed under solvent free conditions in the presence of water. 4-Dimethylaminopyridine also exhibited a beneficial effect on the reactions. The present method enabled hydroazidation of several types of unactivated alkenes with good yields and high regioselectivity.
RhIII-Catalyzed C-H Allylation of Amides and Domino Cycling Synthesis of 3,4-Dihydroisoquinolin-1(2H)-ones with N-Bromosuccinimide
Dai, Huimin,Yu, Chao,Lu, Changsheng,Yan, Hong
, p. 1255 - 1259 (2016/03/16)
A RhIII-catalyzed C-H allylation of electron-deficient arenes, heteroarenes, and alkenes at room temperature was developed with allyl bromide. The reaction was carried out in diethyl ether without dehydration, and C-H activation was assisted by the directing anionic nitrogen of the aniline-derived amide. Following the allylation, a domino cycling synthesis of 3,4-dihydroisoquinolin-1(2H)-ones with N-bromosuccinimide (NBS) through intramolecular aminobromination of the introduced double bond was achieved. A C-H allylation of amides with allyl halides at room temperature and a tandem synthesis of 3,4-dihydroisoquinolin-1(2H)-ones with N-bromosuccinimide (NBS) are reported.
