Amide and Amine Nucleophiles in Polar Radical Crossover Cycloadditions: Synthesis of γ-Lactams and Pyrrolidines
摘要:
In this work we present a direct catalytic synthesis of gamma-lactams and pyrrolidines from alkenes and activated unsaturated amides or protected unsaturated amines, respectively. Using a mesityl acridinium single electron photooxidant and a thiophenol cocatalyst under irradiation, we are able to directly forge these important classes of heterocycles with complete regiocontrol.
Amide and Amine Nucleophiles in Polar Radical Crossover Cycloadditions: Synthesis of γ-Lactams and Pyrrolidines
摘要:
In this work we present a direct catalytic synthesis of gamma-lactams and pyrrolidines from alkenes and activated unsaturated amides or protected unsaturated amines, respectively. Using a mesityl acridinium single electron photooxidant and a thiophenol cocatalyst under irradiation, we are able to directly forge these important classes of heterocycles with complete regiocontrol.
Co-Catalyzed Synthesis of <i>N</i>-Sulfonylcarboxamides from Carboxylic Acids and Sulfonyl Azides
作者:Yue Fang、Zheng-Yang Gu、Shun-Yi Wang、Jin-Ming Yang、Shun-Jun Ji
DOI:10.1021/acs.joc.8b01300
日期:2018.8.17
A Co-catalyzed effective synthesis of N-sulfonylcarboxamides from the reaction of carboxylicacids and organic azides in the presence of isocyanide has been developed. The protocol has the advantages of short time, low temperature, and being oxidant-free, which provides a new and simple approach for the synthesis of N-sulfonylcarboxamides in good to excellent yields with a broad substrate scope.
Organocatalytic Direct <i>N</i>-Acylation of Amides with Aldehydes under Oxidative Conditions
作者:Chenguang Zheng、Xiang Liu、Cheng Ma
DOI:10.1021/acs.joc.7b00457
日期:2017.7.7
The direct oxidative N-acylation reaction of primary amides with aryl/α,β-unsaturated aldehydes was achieved in the presence of azolium salt C3 and an inorganic base using 3,3′,5,5′-tetra-tert-butyldiphenoquinone as the oxidant, thus providing an efficient approach for the synthesis of three types of imide compounds including N-sulfonylcarboxamides, N-sulfinylcarboxamides, and dicarboxyimides in good
Iron(II)-Catalyzed Amidation of Aldehydes with Iminoiodinanes at Room Temperature and under Microwave-Assisted Conditions
作者:Thi My Uyen Ton、Ciputra Tejo、Stefani Tania、Joyce Wei Wei Chang、Philip Wai Hong Chan
DOI:10.1021/jo200284a
日期:2011.6.17
A method for the amidation of aldehydes with PhI=NTs/PhI=NNs as the nitrogen source and an inexpensive iron(II) chloride + pyridine as the in situ formed precatalyst under mild conditions at room temperature or microwave assisted conditions is described. The reaction was operationally straightforward and accomplished in moderate to excellent product yields (20-99%) and with complete chemoselectivity with the new C-N bond forming only at the formylic C-H bond in substrates containing other reactive functional groups. By utilizing microwave irradiation, comparable product yields and short reaction times of 1 h could be accomplished. The mechanism is suggested to involve insertion of a putative iron-nitrene/imido group to the formylic C H bond of the substrate via a H-atom abstraction/radical rebound pathway mediated by the precatalyst [Fe(py)(4)Cl-2] generated in situ from reaction of FeCl2 with pyridine.