Thermal azide–alkene cycloaddition reactions: straightforward multi-gram access to Δ<sup>2</sup>-1,2,3-triazolines in deep eutectic solvents
作者:Filip Sebest、Luis Casarrubios、Henry S. Rzepa、Andrew J. P. White、Silvia Díez-González
DOI:10.1039/c8gc01797b
日期:——
The multi-gram synthesis of a wide range of 1,2,3-triazolines via azide–alkene cycloaddition reactions in a Deep Eutectic Solvent (DES) is reported. The role of DES in this transformation as well as the origin of the full product distribution was studied with an experimental/computational-DFT approach.
Aziridines undergo ring opening readily with various thiols in the presence of 5 mol% bismuthtriflate under very mild reaction conditions to afford the corresponding β-aminosulfides in excellent yields with high regioselectivity.
Styrene derivatives reacted with diphenyl(trifluoromethanesulfonyloxy)sulfonium trifluoromethanesulfonate (1) at low temperature to afford 2-arylethenyl(diphenyl)sulfonium triflates (2). Treatment of 2 with primary amines gave the corresponding 2-arylaziridines in high yields. One-pot synthesis of various aziridines was also successfully carried out without isolation of the intermediate 2.
“On Water”: Efficient Iron-Catalyzed Cycloaddition of Aziridines with Heterocumulenes
作者:Mani Sengoden、Tharmalingam Punniyamurthy
DOI:10.1002/anie.201207746
日期:2013.1.7
In suspension: The reaction of aziridines with heterocumulenes in the presence of Fe(NO3)3⋅9 H2O in aqueous suspension provides access to functionalized five‐membered heterocycles in good to high yields. This protocol has a wide substrate scope, is simple, and uses a nontoxic and cheap catalyst.
Stereoselective Copper-Catalyzed Cross-Coupling of Aziridines with Benzimidazoles via Nucleophilic Ring Opening and C(sp<sup>2</sup>)–H Functionalization
A copper-catalyzed cross-coupling of 2-alkyl-/2-arylaziridines with benzimidazoles is reported. The reactions involve a regiospecific ring opening of aziridines with benzimidazoles to give benzoimidazolylethylamine derivatives that lead to dehydrogenative cross-coupling between C(sp2)-H and N–H bonds to produce dihydroimidazobenzimidazoles. Optically active 2-arylaziridines can be stereoinvertivebly