Researching the role of sodium borohydride in novel reductive alkylations

Abstract

Formerly, our lab developed a one-pot synthesis for the reductive alkylation of monosubstituted malononitriles. This chemistry has been expanded to a variety of different compounds by replacing one of the cyano groups on the malononitrile with another highly electron withdrawing group such as an ester, sulfone, or ketone. , The cyanoacetates, sulfonylacetonitriles and 13-ketonitriles were then reacted with different ketones using sodium borohydride to obtain the reduced monosubstituted derivatives. The reaction proceeded via Knoevenagel condensation (creating the carbon-carbon double bond) and this alkene is selectively reduced using the borohydride. A two-pot synthesis in which the alkylation and reduction are achieved in separate steps for aldehydes and this is being optimized for the reductive alkylation in a one-pot synthesis. Recent literature experiments have formed the Knoevenagel product without the assistance of a catalyst.