From Cyclic CF3-ketimines to a Family of Trifluoromethylated Nazlinine and Trypargine Analogues

An efficient (one- and two-step) synthesis of trifluoromethylated derivatives of the natural alkaloids nazlinine, trypargine, and homotrypargine was elaborated. Trifluoromethyl-substituted 5-7-membered cyclic imines were used as a masked carbonyl component in the Pictet-Spengler reaction with various tryptamines. As a result, this approach opens access to a family of alkaloid-like compounds bearing a CF3 group at position 1 of tetrahydro-β-carboline. © 2016 American Chemical Society

Diastereoselectivity of Azido-Ugi Reaction with Secondary Amines. Stereoselective Synthesis of Tetrazole Derivatives

The diastereoselectivity of azido-Ugi reaction with cyclic amines was investigated. It was found that the reaction with α-substituted five- to seven-membered cyclic amines proceeds very efficiently to provide high control of diastereoselectivity (≤100% de) under mild conditions. Target tetrazole-derived products were isolated in excellent yields (≤98%). The reaction has a broad scope in terms of its amine, aldehyde, and isocyanide nature. It was found that the diastereoselectivity of the reaction depends on the ring size of the starting cyclic amines. More rigid piperidines provided the highest selectivity of the reaction. Using benzyl isocyanide, the prepared N-benzyl tetrazoles can be deprotected by hydrogenolysis to form the corresponding NH tetrazoles in high yields. © 2017 American Chemical Society

Synthesis of blue light emitting heterocyclesviacyclization of 2-pyridine derived 4-azido-r1,2,3-triazoles

An efficient synthesis of 2-pyridine derived 4-azido-1,2,3-triazoles was elaborated using the corresponding dichlorodiazadienes as precursors. The reaction of the prepared 2-azine substituted diazadienes with sodium azide permits the preparation of target triazoles isolated in up to 92% yield. Subsequent thermal cyclization was studied. Elimination of molecular nitrogen promoted the cyclization of nitrene at the azine nitrogen. As a result, a family of 2H-[1,2,3]triazolo[4′,5′:3,4]pyrazolo[1,5-a]pyridin-5-ium-4-ides was prepared. The synthesized compounds are members of a new heterocyclic system. Moreover, these compounds are new attractive blue light emitting molecules. © The Royal Society of Chemistry 2021

Synthesis of Pyridazin-3(2H)-one Derivatives by the Reaction of CH-Acids with Dichlorodiazadienes

The reactions of 4,4-dichloro-1,2-diazabuta-1,3-dienes with dimethyl malonate, cyanoacetic esters and ethyl acetoacetate provided straightforward access to highly functionalized pyridazine derivatives. The approach was found to be very general for the highly efficient synthesis of various pyridazine derivatives which can be isolated in moderate to excellent yields. The possibility of their subsequent functionalization was demonstrated. Moreover, the absorption characteristics in the UV/Vis-range and luminescence were studied for all synthesized compounds. © 2020 Wiley-VCH Gmb

From Cyclic CF3-ketimines to a Family of Trifluoromethylated Nazlinine and Trypargine Analogues

An efficient (one- and two-step) synthesis of trifluoromethylated derivatives of the natural alkaloids nazlinine, trypargine, and homotrypargine was elaborated. Trifluoromethyl-substituted 5-7-membered cyclic imines were used as a masked carbonyl component in the Pictet-Spengler reaction with various tryptamines. As a result, this approach opens access to a family of alkaloid-like compounds bearing a CF3 group at position 1 of tetrahydro-β-carboline. © 2016 American Chemical Society

Diastereoselectivity of Azido-Ugi Reaction with Secondary Amines. Stereoselective Synthesis of Tetrazole Derivatives

The diastereoselectivity of azido-Ugi reaction with cyclic amines was investigated. It was found that the reaction with α-substituted five- to seven-membered cyclic amines proceeds very efficiently to provide high control of diastereoselectivity (≤100% de) under mild conditions. Target tetrazole-derived products were isolated in excellent yields (≤98%). The reaction has a broad scope in terms of its amine, aldehyde, and isocyanide nature. It was found that the diastereoselectivity of the reaction depends on the ring size of the starting cyclic amines. More rigid piperidines provided the highest selectivity of the reaction. Using benzyl isocyanide, the prepared N-benzyl tetrazoles can be deprotected by hydrogenolysis to form the corresponding NH tetrazoles in high yields. © 2017 American Chemical Society