Metal-Templated Assembly of Cyclopropane-Fused Diazepanones and Diazecanones via exo- trig Nucleophilic Cyclization of Cyclopropenes with Tethered Carbamates.

A strain-release-driven, cation-templated nucleophilic 7- and 8- exo-trig-cyclization of tethered Boc-protected amines to cyclopropenes is described. The featured reaction proceeds in diastereo- and regioselective fashion and allows for preparation of the corresponding 2,5-diazabicyclo[5.1.0]octan-6-ones and 2,6-diazabicyclo[6.1.0]nonan-7-ones as sole products in high yields. Preliminary studies on anticancer activities of these novel cyclopropane-fused medium heterocycles were performed.

Desymmetrization of Cyclopropenes via the Potassium-Templated Diastereoselective 7- exo- trig Cycloaddition of Tethered Amino Alcohols toward Enantiopure Cyclopropane-Fused Oxazepanones with Antimycobacterial Activity.

A strain-release-driven, cation-templated intramolecular nucleophilic addition of tethered alkoxides to prochiral cyclopropenes is described. Employment of chiral ß- and γ-amino alkoxides allowed for highly diastereoselective assembly of a small series of enantiopure cyclopropane-fused oxazepanones. It was shown that the chiral center at C-4 plays a crucial role in controlling desymmetrization of the cyclopropenyl moiety, instigated by a profound potassium-templated effect. The preliminary biological activities of the new cyclopropane-fused medium heterocycles against Gram-positive bacteria, Gram-negative bacteria, mycobacteria, cancer cells, and fungus were evaluated.