Alkylation of 5-Substituted Tetrazoles with Various Alcohols in 1,2-Dichloroethane in the Presence of BF3·Et2O
摘要:
The alkylation of 1H-tetrazole, 5-methyl-1H-tetrazole, and 5-phenyl-1H-tetrazole with primary, secondary, and tertiary alcohols, including benzylic and allylic ones, have been studied in 1,2-dichloroethane in the presence of boron trifluoride-diethyl ether complex. Neither primary nor secondary saturated alcohols alkylated tetrazoles in the given system. Tertiary alcohols suchtert-butyl alcohol and adamantan-1-ol reacted with unsubstituted and 5-substituted tetrazoles to give 70-85% of the corresponding 2-alkyl-5-R-tetrazoles with high regioselectivity. The alkylation of 1H-tetrazole with benzyl alcohol afforded 55% of 2-benzyl-2H-tetrazole as the only product. The alkylation of 1H-tetrazole with various allylic alcohols led to the formation of mixtures of 2-alkyl-2H-tetrazoles with isomeric alkyl substituents.
Formal Aza‐Wacker Cyclization by Tandem Electrochemical Oxidation and Copper Catalysis
作者:Xiangli Yi、Xile Hu
DOI:10.1002/anie.201814509
日期:2019.3.26
In oxidative electrochemical organic synthesis, radical intermediates are often oxidized to cations on the way to final product formation. Herein, we describe an approach to transform electrochemically generated organic radical intermediates into neutral products by reaction with a metalcatalyst. This approach combines electrochemical oxidation with Cu catalysis to effect formal aza‐Wacker cyclization
attachment and inherent catalyst poisoning by heterocycles demand alternate routes for site selective functionalization of their distal C-H bonds. Utilizing non-productive coordinating property to hold the heterocycle into the cavity of a template system in a host-guest manner, we report distal C-H alkylation (C-5 of quinoline and thiazole, C-7 of benzothiazole and benzoxazole) of heterocycles. Upon complexation
Intermolecular oxidative amination of unactivated alkenes by dual photoredox and copper catalysis
作者:Xiangli Yi、Xile Hu
DOI:10.1039/d0sc05952h
日期:——
photochemical generation of amidyl radicals with Cu-mediated β-H elimination of alkyl radicals, we have developed an intermolecular oxidative amination of unactivated alkenes. The reaction relies on tandem photoredox and copper catalysis, and works for both terminal and internal alkenes. The radical nature of the reaction and the mild conditions lead to high functional group tolerance.
Intramolecular Carbonyl Nitroso Ene Reaction Catalyzed by Iron(III) Chloride/Hydrogen Peroxide as an Efficient Tool for Direct Allylic Amination
作者:Duncan Atkinson、Mikhail A. Kabeshov、Mark Edgar、Andrei V. Malkov
DOI:10.1002/adsc.201100632
日期:2011.12
A mild, simple oxidation protocol employing iron(III) chloride as a catalyst and hydrogen peroxide as a stoichiometric oxidant was found to be compatible with an intramolecular carbonyl nitroso ene reaction and allowed us to efficiently convert hydroxamic acids into a diverse range of 1,2- and 1,3-amino alcohol derivatives in a single operation.
High Turnover Numbers for the Catalytic Selective Epoxidation of Alkenes with 1 atm of Molecular Oxygen We acknowledge T. Hayashi (The University of Tokyo), M. Wada (Nippon Shokubai Co., Ltd.), and Y. Sumita (Nippon Shokubai Co., Ltd.) for their help with experiments. This work was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture of Japan.