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 and Reactivity Profile of Ylidenemalononitrile Enamines and Their Ester Analogs Towards Electrophiles and Nucleophiles
作者:Ashley R. Longstreet、Daniel Rivalti、D. Tyler McQuade
DOI:10.1021/acs.joc.5b01169
日期:2015.9.4
Herein, we describe the synthesis and reactivity of enamines derived from ylidenemalononitriles and ylidenecyanoacetates. The enamine scope was expanded by (1) increasing yields of aldehyde-derived ylidenemalononitriles, (2) incorporating silyl functionalities, and (3) using other amide acetals to expand the substitution patterns of pyridines resulting from enamine cyclization. In addition, methods
An expedient approach to synthesize fluorescent 3-substituted 4H-quinolizin-4-ones via (η<sup>4</sup>-vinylketene)-Fe(CO)<sub>3</sub> complexes
作者:Alfredo Rosas-Sánchez、Rubén A. Toscano、José G. López-Cortés、M. Carmen Ortega-Alfaro
DOI:10.1039/c4dt03021d
日期:——
From simple starting materials, an efficient methodology for the synthesis of 3-substituted 4H-quinolizin-4-ones using (η4-vinylketene)-Fe(CO)3 complexes as key intermediates was developed. Fluorescent properties and quantum yields were determined.
Unexpected metal-free synthesis of trifluoromethyl arenes <i>via</i> tandem coupling of dicyanoalkenes and conjugated fluorinated sulfinyl imines
作者:Alvaro Sanz-Vidal、Daniel Gaviña、Lia Sotorríos、Enrique Gómez-Bengoa、Fernando López Ortiz、María Sánchez-Roselló、Carlos del Pozo
DOI:10.1039/d1cc03161a
日期:——
A novel strategy for the synthesis of policyclic trifluoromethyl arenes has been devised. It involves a DBU-promoted tandem cycloaromatization reaction of dicyanoalkenes and fluorinated conjugated sulfinyl imines. This unprecedented transformation is a metal-free and air-tolerant process that takes place from readily available starting materials under mild reaction conditions.
A novel access to highly functionalized 2-aminonicotinonitriles via efficient annulations of [small alpha]-keto vinyl azides and [small alpha],[small alpha]-dicyanoalkenes is described. This annulation was achieved via base-mediated ring-openings and intramolecular rearrangements. A possible...