Synthesis of carbamates from diethoxycarbonyl hydrazine derivatives by E1cB eliminative cleavage of the N-N'-bond rather than reduction.

Treatment of diethoxycarbonyl hydrazine derivatives with methyl bromoacetate/Cs(2)CO(3)/MeCN at 50 degrees C followed by heating to 80 degrees C resulted in N-N' bond cleavage to the corresponding carbamates.

Mechanistic implications in the Morita-Baylis-Hillman alkylation: isolation and characterization of an intermediate.

An intermediate phosphonium salt has never been isolated from the Morita-Baylis-Hillman (MBH) reaction. Due to the weakly basic counterion produced in the MBH alkylation and allylation reactions, the reaction can be stopped after electrophilic attack on the zwitterionic enolate and an intermediate isolated. Upon analysis of the crystal structure, a trans geometry is observed, suggesting that there is no electrostatic interaction between phosphorus and oxygen in the zwitterionic enolate that undergoes alkylation, thus giving new mechanistic insight into the MBH reaction.

Unprecedented reactivity in the Morita-Baylis-Hillman reaction; intramolecular alpha-alkylation of enones using saturated alkyl halides.

sp3 Hybridized electrophiles, never before used in the organomediated Morita-Baylis-Hillman reaction, now facilitate the formation of five- and six-membered enone cycloalkylation products.