Phosphine-catalyzed asymmetric additions of malonate esters to γ-substituted allenoates and allenamides

Because carbonyl groups are ubiquitous in organic chemistry, the ability to synthesize functionalized carbonyl compounds, particularly enantioselectively, is an important objective. We have developed a straightforward and versatile method for catalytic asymmetric carbon-carbon bond formation at the gamma-position of carbonyl compounds, specifically, phosphine-catalyzed additions of malonate esters to gamma-substituted allenoates and allenamides. Mechanistic studies have provided insight into the reaction pathway.