Decarboxylative alkenylation

Starting with alkyl carboxylic acids, a simple olefin synthesis using any substitution pattern or geometry, based on amide-bond synthesis with nickel- or iron-based catalysis, is described. Simplified olefin synthesis Olefins are ubiquitous functional groups in organic chemistry and are typically installed in small molecules by the formation of a carbon–carbon double bond. Here, Phil Baran and colleagues report a decarboxylative alkyl-vinyl cross-coupling that offers a cheap and simple route to olefins with defined geometry and substitution pattern. The nickel or iron catalysts extract carbon dioxide from the carboxylic acid, which is activated in a similar way to peptide-bond formation. The alkene is then attached with a vinyl zinc reagent. The authors exemplify their method by preparing more than 60 olefins and synthesizing 16 natural products. One such example offers a short route to macrocyclic polyketides from the commodity chemical diethyl tartrate. Olefin chemistry, through pericyclic reactions, polymerizations, oxidations, or reductions, has an essential role in the manipulation of organic matter 1 . Despite its importance, olefin synthesis still relies largely on chemistry introduced more than three decades ago, with metathesis 2 being the most recent addition. Here we describe a simple method of accessing olefins with any substitution pattern or geometry from one of the most ubiquitous and variegated building blocks of chemistry: alkyl carboxylic acids. The activating principles used in amide-bond synthesis can therefore be used, with nickel- or iron-based catalysis, to extract carbon dioxide from a carboxylic acid and economically replace it with an organozinc-derived olefin on a molar scale. We prepare more than 60 olefins across a range of substrate classes, and the ability to simplify retrosynthetic analysis is exemplified with the preparation of 16 different natural products across 10 different families.