An efficient carbonylative coupling reaction of two equivalents of 1,3-butadiene, yielding aryl nona-3,8-dienoate esters, is performed with phenols as nucleophile, and promoted by palladium-based catalysts. Optimization study reveals the key role of benzoic acid as a cocatalyst. The suggested catalyst combination enables the conversion of a wide scope of variously substituted phenols into corresponding esters with a high yield. Further tests were performed with diphenols, naturally-occurring phenols and an industrial grade Kraft lignin, thus, indicating the scope of this reaction for transforming industrially relevant polyphenolic structures.
Keywords: butadiene; carbonylation; lignin; palladium; phenol.
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