Synthesis of Oxa-aza- and Bis-oxathiaaza[3.3.3]propellanes from Dicyanomethylene-1,3-indanedione and 2,5-Dithiobiureas

Abstract

An efficient route for the synthesis of oxa-aza-and bis-oxathiaaza[3.3.3]propellanes via reactions of symmetrical and unsymmetrical N 1 ,N 2-disubstituted hydrazine-1,2-dicarbothioamides (2,5dithiobiureas) with (1,3-dioxo-2,3-dihydro-1H-inden-2-ylidene)propanedinitrile in tetrahydrofuran is described. The rationale behind these conversions involving nucleophilic addition on the dicyanomethylene carbon atom is presented. The structures of these unusual products are confirmed by X-ray crystal structure analysis.

Bis‐thiourea Derivatives and Their Utility in Synthesis of Mono‐heterocyclic, Bis‐heterocyclic, and Fused Heterocyclic Systems

“…Reaction of the inden‐2‐ylidenepropanedinitrile 151 with the symmetrical and unsymmetrical 1,6‐disubstituted‐2,5‐dithiobiurea 2 (in 3:1 molar ratio) in tetrahydrofuran was reported at room temperature for 96 h and resulted in the formation of a mixture of three products: the bis‐oxathiaaza[3.3.3]propellane derivative 159 along with the 1,3,4‐thiadiazole 160 and the oxa‐aza[3.3.3]propellane 161 (Scheme ) .…”

An Update of the Use of Thiocarbohydrazides and Thiosemicarbazides in the Preparation of Heterocycles and Their Biological Importance

“…Synthesis of bis‐oxathiaaza[3.3.3] propellanes 218a – e was performed, in 58–63% yields, by nucleophilic attack of N 1 , N 2 disubstituted hydrazine‐1,2‐dicarbothioamides (2,5‐dithiobiureas) 89a – e and 44 with stirring at r.t (open to air) in THF (Scheme ) .…”

Far Away from Flatland. Synthesis and Molecular Structure of Dihetera[3.3.n]propellanes and Trihetera[3.3.n]propellanes: Advanced Analogues of Morpholine/Piperazine

“…Known synthetic approaches to oxapropellanes relied on the construction of the tetrahydrofuran ring via reduction of the corresponding bicyclic dicarboxylic acid derivatives, followed by intramolecular cyclization of the resulting diol (Scheme , method A). ,, Meanwhile, amination of these starting derivatives with subsequent imide reduction was applied for the preparation of azapropellanes. ,− The required starting materials were generally obtained by double alkylation, the Weiss–Cook reaction (i.e., double condensation of 1,2-dicarbonyl compounds and acetone dicarboxylates), , or various rearrangements. , Alternative approaches included [2 + 2] or [4 + 2] − cycloadditions (method B), ring-closing metathesis (method C), − β-hydroxy- or β-formylester lactonization–reduction (method D), and recyclizations of polycyclic derivatives. − …”