Iron-Catalyzed Annulation of 1,2-Diamines and Diazodicarbonyls for Diverse and Polyfunctionalized Quinoxalines, Pyrazines, and Benzoquinoxalines in Water
作者:Rameshwar Prasad Pandit、Sung Hong Kim、Yong Rok Lee
DOI:10.1002/adsc.201600503
日期:2016.11.17
construction of polyfunctionalized quinoxalines has been developed. The key strategy includes the one‐pot domino N−H insertion, cyclization, and oxidation reactions. This protocol offers a safe and mild synthetic approach to access a variety of quinoxalinederivatives in high yields. This methodology also allows the formation of biologically interesting pyrazines and benzoquinoxalines.
Construction of Multifunctionalized Azopyrazoles by Silver- Catalyzed Cascade Reaction of Diazo Compounds
作者:Rameshwar Prasad Pandit、Yong Rok Lee
DOI:10.1002/adsc.201500197
日期:2015.8.24
silver trifluoromethanesulfonate (AgOTf)‐catalyzed cascade reaction of α‐diazo‐β‐keto esters with two arylhydrazines or two arylhydrazine hydrochlorides. This cascade reaction included pyrazolone formation, NHinsertion, and oxidation. For the synthesis of more diverse azopyrazoles bearing two different aromatic rings, the silver(I)‐catalyzed cascade reaction of 4‐diazopyrazol‐3‐one with arylhydrazine
Rhodium(II)- and Copper(II)-Catalyzed Reactions of Enol Diazoacetates with Nitrones: Metal Carbene versus Lewis Acid Directed Pathways
作者:Yu Qian、Xinfang Xu、Xiaochen Wang、Peter J. Zavalij、Wenhao Hu、Michael P. Doyle
DOI:10.1002/anie.201202525
日期:2012.6.11
A complimentary cat.: Copper(II) hexafluoroantimonate catalyzes the formal [3+3] cycloaddition of Lewisacid activated nitrones and vinyl diazoacetates to produce 3,6‐dihydro‐1,2‐oxazines in yields of up to 96 % and diastereoselectivities greater than 25:1 (see scheme). This process compliments the metalcarbenepathway that is catalyzed by rhodium(II) species.
Copper-catalyzed condensation of imines and α-diazo-β-dicarbonyl compounds: modular and regiocontrolled synthesis of multisubstituted pyrroles
作者:Wei Wen Tan、Naohiko Yoshikai
DOI:10.1039/c5sc02322j
日期:——
In the presence of a copper(II) catalyst, enolizable imines bearing various N-substituents and α-diazo-β-ketoesters undergo denitrogenative and dehydrative condensation to afford highly substituted pyrroles in moderate to good yields with exclusive regioselectivity. The reaction likely involves nucleophilic addition of the imine nitrogen to a copper carbenoid, tautomerization of the resulting azomethine
Donor–Acceptor–Acceptor 1,3-Bisdiazo Compounds: An Exploration of Synthesis and Stepwise Reactivity
作者:Dylan J. Abrams、Huw M. L. Davies、Erik J. Sorensen
DOI:10.1021/acs.orglett.0c00103
日期:2020.3.6
from the decomposition of diazo compounds, are valued for their capacity to perform a variety of transformations. A unique class of acyclic, bis-diazo compounds, the donor-acceptor-acceptor 1,3-bisdiazo compounds, are described herein. These compounds are available from acyclic β-keto esters and especially reactive at the donor-acceptor diazo unit. These bisdiazo compounds react smoothly with rhodium acetate