Boron Trifluoride-Mediated Cycloaddition of 3-Bromotetrazine and Silyl Enol Ethers: Synthesis of 3-Bromo-pyridazines
作者:Simon D. Schnell、Jorge A. González、Jan Sklyaruk、Anthony Linden、Karl Gademann
DOI:10.1021/acs.joc.1c01384
日期:2021.9.3
regiocontrol remains difficult. We achieved the Lewis acid-mediated inverse electron demand Diels–Alder reaction between 3-monosubstituted s-tetrazine and silylenolethers and obtained functionalized pyridazines. In the case of 1-monosubstituted silylenolethers, exclusive regioselectivity was observed. Downstream functionalization of the resulting 3-bromo-pyridazines was demonstrated utilizing several cross-coupling
Visible-lightphotoredoxcatalysis has been utilized in a new multicomponent reaction forming β-functionalized δ-diketones under mild conditions in an operationally convenient manner. Single-electron reduction of in situ generated carboxylic acid derivatives forms acyl radicals that react further via 1,2-acylalkylation of olefins in an intermolecular, three-componentscascade reaction, giving valuable
Copper-Catalyzed Fluoroolefination of Silyl Enol Ethers and Ketones toward the Synthesis of β-Fluoroenones
作者:Yanlin Li、Jing Liu、Shuang Zhao、Xuzhao Du、Minjie Guo、Wentao Zhao、Xiangyang Tang、Guangwei Wang
DOI:10.1021/acs.orglett.7b03700
日期:2018.2.16
A general and facile synthetic method for β-fluoroenones from silylenolethers or ketones, with a copper–amine catalyst system, has been developed. The reaction proceeded by a tandem process of difluoroalkylation–hydrolysis–dehydrofluorination. This method is characterized by high yields, excellent Z/E ratios, a low-cost catalyst, and a broad substrate scope. The synthetic potential of β-fluoroenones
Photocatalytic Vicinal Aminopyridylation of Methyl Ketones by a Double Umpolung Strategy
作者:Honggu Im、Wonjun Choi、Sungwoo Hong
DOI:10.1002/anie.202008435
日期:2020.9.28
umpolung strategy for the vicinal aminopyridylation of ketones was developed using pyridinium N−N ylides. The inversion of the polarity of the pyridinium N−N ylides by single‐electron oxidation successfully enables radical‐mediated 1,3‐dipolar cycloadditions with enolsilanes formed in situ from ketones, followed by homolytic cleavage of the N−N bond. Intriguingly, the nucleophilic amino and electrophilic
The synthesis of pyrroles and oxazoles based on gold α-imino carbene complexes
作者:Nicole S. Y. Loy、Subin Choi、Sunggak Kim、Cheol-Min Park
DOI:10.1039/c6cc01742h
日期:——
Cationic gold complexes of [small alpha]-oximimino carbenes have been identified to react with nucleophiles with attenuated reactivity including enol ethers and nitriles. These findings allowed us to develop highly efficient synthesis...