Unsymmetrical α,ω-Difunctionalized Long-Chain Compounds via Full Molecular Incorporation of Fatty Acids

Abstract

α,ω-Difunctionalized long-chain compounds A-(CH2)n-B are valuable intermediates and monomers. Unsymmetrical compounds with two different functional groups (A ≠ B) are, however, only accessible by multistep traditional organic syntheses to date. We report on their generation in a single step by isomerizing alkoxycarbonylations of the double bond deep in the chain of oleic derivatives. The compatibility with amide, nitrile and imide functionalities in the substrate allows for the formation with high linear selectivities (ca. 90%) and conversions (70 to 96%) of unsymmetric diesters, ester–amides, ester-nitriles and ester-(N-imides) in which these functional groups are terminally attached to a ≥ 17 methylene unit chain. These products further provide access to carboxylic acid-esters, alcohol-esters and amino-esters, and polymers from these AB-monomers. Undesired transesterifications that scramble the A and B functionalities are suppressed completely (<0.1%) by the utilization of a Pd(II) catalyst precursor devoid of acid additives in the presence of amine base.