Visible-Light-Mediated Intermolecular Radical Conjugate Addition for the Construction of Vicinal Quaternary Carbon Centers
作者:Lei Li、Lili Fang、Weiping Wu、Jin Zhu
DOI:10.1021/acs.orglett.0c01724
日期:2020.7.17
The visible light-driven organophotoredox catalysis is reported for the construction of vicinal quaternary carbon centers. Intermolecular conjugateaddition of alkyl radicals, derived from 2,2-disubstituted dihydroquinazolinones, to Michael acceptors under blue light irradiation and rhodamine B catalysis allows the facile assembly of diverse, vicinal secondary/quaternary, tertiary/quaternary, and
Synthesis of Flavanone and Quinazolinone Derivatives from the Ruthenium-Catalyzed Deaminative Coupling Reaction of 2′-Hydroxyaryl Ketones and 2-Aminobenzamides with Simple Amines
作者:Krishna Gnyawali、Pandula T. Kirinde Arachchige、Chae S. Yi
DOI:10.1021/acs.orglett.1c03870
日期:2022.1.14
deaminative coupling reaction of 2′-hydroxyaryl ketones with simple amines to form 3-substituted flavanone products. The analogous deaminative coupling reaction of 2-aminobenzamides with branched amines directly formed 3,3-disubstituted quinazolinone products. The catalytic method efficiently installs synthetically useful flavanone and quinazolinone core structures without employing any reactive reagents.
Ketone-derived 2,3-dihydroquinazolinones in <i>N</i>-heteroarene C–H alkylation <i>via</i> C–C bond scission under oxidative metal catalysis
作者:Pinku Prasad Mondal、Amit Pal、Athira K Prakash、Basudev Sahoo
DOI:10.1039/d2cc04947c
日期:——
activation of pre-aromatic 2,3-dihydroquinazolinone to generate an alkyl radical, supported by mechanistic studies. In addition to the broad scope, good functionality tolerance, late stage functionalization of APIs, and synthesis of a novel Papaverine analogue, the utilization of an N-heteroarene C–H bond and ketone as a non-trivial alkyl radical source represents the salient feature of this method.
α-stereocenter, thus enhancing the carbogenic complexity and tolerating diverse functionalities. Additional to telescopic synthesis and product diversification, this method features a radical dicarbofunctionalization of conjugated N-(arylsulfonyl)acrylamides with a nucleophilic alkyl radical precursor (dihydroquinazolinone) utilizing oxygen as a green oxidant at ambient temperature.
Deconstructive alkynylation of an unstrained ketone catalyzed by an organic photocatalyst under blue light irradiation is reported for the first time. A broad substrate scope with up to 63 examples, excellent functional group tolerance, and gram scale reaction demonstrated the practicality of this novel alkynylation method. The dihydroquinazolinone derivative of trifluoroacetophenone had been proved