Amide-Group-Directed Protonolysis of Cyclopropane: An Approach to 2,2-Disubstituted Pyrrolidines
作者:Marija Skvorcova、Aigars Jirgensons
DOI:10.1021/acs.orglett.7b00584
日期:2017.5.19
Regioselective protonolytic C–C bond cleavage of acylated aminomethyl cyclopropanes can be achieved using trifluoroacetic acid. The intermediate tertiary carbenium ion undergoes an intramolecular amination to give 2,2-substituted pyrrolidines. The strength of the acid and the amine substituent are important factors to achieve high regioselectivity, suggesting intramolecular proton transfer from the
5-<i>Exo</i> versus 6-<i>Endo</i> Cyclization of Primary Aminyl Radicals: An Experimental and Theoretical Investigation
作者:Feng Liu、Kun Liu、Xinting Yuan、Chaozhong Li
DOI:10.1021/jo7015967
日期:2007.12.1
The cyclization of neutral primary pent-4-enylaminyl radicals was investigated experimentally and theoretically. Unlike the corresponding secondary aminyl radicals, primary pent-4-enylaminyl radicals underwent efficient cyclization to afford the pyrrolidine and/or piperidine products in good to high yields. While the simple pent-4-enylaminyl radical gave predominately the 5-exo, cyclization product, 4-chloropent-4-enylarninyl radicals led to the formation of the corresponding 6-endo cyclization products in excellent regioselectivity. Theoretical calculations revealed that the 5-exo cyclization rate of primary aminyl radicals is about 3-4 orders of magnitude higher than that of secondary aminyl radicals.
Divergent Electrochemical Carboamidation of Cyclic Amines
作者:Feijun Wang、Kevin J. Frankowski
DOI:10.1021/acs.joc.1c02534
日期:2022.1.21
sequence that affords either cyclic β-amidoamine products via direct functionalization or linear hydroxybisamide products via a ringopening pathway. The reaction pathway was dependent on the nature of the N-acyl activating group, with carbamate groups favoring direct isocyanide addition to the N-acyliminium ion intermediate and the benzoyl activating group favoring the ring opening–functionalization
Metal-Free Oxidative Functionalization of C(sp<sup>3</sup>)–H Bond Adjacent to Oxygen and Radical Addition to Olefins
作者:Wei Zhou、Ping Qian、Jincan Zhao、Hong Fang、Jianlin Han、Yi Pan
DOI:10.1021/acs.orglett.5b00088
日期:2015.3.6
A DTBP-promoted oxidative functionalization of a C(sp3)–Hbond adjacent to oxygen and intermolecular radical addition to olefins without use of any metal catalyst or photoredox catalysis is reported. The reaction has a wide scope of olefin, alcohol, and cycloether substrates, which provides an easy way for direct preparation of α,ω-amino alcohols.