Olga I. Shmatova

Synthesis of Tetrazole-Derived Organocatalysts via Azido-Ugi Reaction with Cyclic Ketimines

A new route to tetrazole-derived cyclic amines based on the TMSN3-modified Ugi reaction with 2-substituted cyclic imines was elaborated. The reaction allows the direct preparation of five-, six-, and seven-membered cyclic amines substituted with a tetrazole ring, which are important types of organocatalysts. The scope and limitations of this method are discussed. In the case of the Ugi reaction with benzyl isocyanide, the N-substituted tetrazoles can be easily debenzylated under catalytic hydrogenation conditions to form NH-tetrazoles in quantitative yields. It was demonstrated that both enantiomers of tetrazole-derived cyclic amines can be prepared by resolution with tartaric acid, thereby initiating a simple route to chiral derivatives. One of the obtained chiral tetrazoles was efficiently used as an organocatalyst in the amination reaction.

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.

Synthesis of Chiral Piperazinones Using Amphoteric Aziridine Aldehyde Dimers and Functionalized Isocyanides

We have evaluated a range of functionalized isocyanides in the aziridine aldehyde-driven multicomponent synthesis of piperazinones. High diasteroselectivity for each isocyanide was observed. A theoretical evaluation of the reaction course corroborates the experimental data. Moreover, the reactivity of cis- and trans-configured aziridine aldehyde dimers has been compared. This study further probes the dimer-driven mechanism of cyclization and enables an efficient access to a wide range of chiral piperazinones bearing functionalized side chains.