No abstract

The kinetic resolution of racemic 2,3-allenoates was realized via 1,3-dipolar cycloaddition by using a bisphosphoric acid catalyst, affording the optically active 2,3-allenoates and 3-methylenepyrrolidine derivatives in high yields and enantioselectivities.

α-Aminonitriles inaccessible by traditional Strecker chemistry are obtained in redox-neutral fashion by direct amine α-cyanation/N-alkylation or alternatively, α-aminonitrile isomerization. These unprecedented transformations are catalyzed by simple carboxylic acids.

The first use of vicinal diols, ketols, or diones as 2 2π components in metal-catalyzed [2+2+2] cycloaddition is described. Using ruthenium(0) catalysts, 1,6-diynes form ruthenacyclopentadienes that engage transient diones in successive carbonyl addition. Transfer hydrogenolysis of the resulting ruthenium(II) diolate mediated by the diol or ketol reactant releases the cycloadduct with regeneration of ruthenium(0) and the requisite dione.