The 3-aza-Cope rearrangements of 3-azoniahexa-1,5-diene (1), 3-azoniahex-1-ene-5-yne (3), and 3-azahex-1-ene-5-yne (5) were investigated up to the coupled-cluster level, CCSD(T), by using a valence triple-zeta basis set. Activation barriers and geometrical parameters of the transition states are provided. Conformational studies were performed for all reactants and products of the reactions. Sol...

The first total synthesis of (+/-)-actinophyllic acid (1) is reported. Key steps of this synthesis include an intramolecular oxidative coupling of ketone and malonic ester enolates and an aza-Cope-Mannich rearrangement that assembled the core structure of the natural product's unique ring system. The synthesis was accomplished from di-tert-butyl malonate in 8% overall yield by a concise sequenc...

A vinylsilane-ketiminium ion cyclization involving iminium species derived from amines 6 and 7 was investigated experimentally as a possible approach to some biologically interesting 1-azaspirocycles. However, even under conditions of microwave irradiation at high temperatures no such cyclization was observed whereas (in line with previous results) the corresponding vinylsilane-aldiminium ion c...

Thermal rearrangement of 2-thiabicyclo[ 3.2.0]hepta-3,6-diene-6,7-dicarbonitriles 1-3 to their 4,5-dicarbonitrile isomers 4-6 takes place at 110-140 "C in yields of 82-84%. The reactions are first order with rates almost independent of the polarity of the solvent. Activation parameters (m = 120-140 kJ mol-' and AS* = 0 J K-l mol-') are in agreement with a concerted symmetry-allowed antarafacial...