Direct Synthesis of Adipic Esters and Adiponitrile via Photoassisted Cobalt‐Catalyzed Alkene Hydrodimerization

Abstract

The direct hydrodimerization of acrylates and acrylonitrile offers a general streamlined access to industrially important intermediates to nylon 6,6. However, a practical catalytic method for this process has thus far underdeveloped owing to the challenges in regioselectivity and environmental compatibility of applied reagents. Here, we report a cobalt‐catalyzed tail‐to‐tail hydrodimerization of activated alkenes driven by a visible‐light photoredox catalysis at ambient temperature, which is applicable to both adipates and adiponitrile synthesis from potentially renewable feedstocks. This protocol utilizes half equivalent of hantzsch ester as a recyclable two‐electron and two‐proton donor with the assistance of catalytic amount of base as a proton shuttle, and has been shown to be highly regioselective and efficient for hydrodimerizing various activated alkenes to 1,4‐difunctionalized butane derivatives.

Regio- and Stereoselective Reductive Coupling of Alkynes and Crotononitrile

“…However, scarce examples have been reported in the asymmetric reductive coupling of alkynes and alkenyl compounds, which are also easily available and widely used starting materials. Competitive homocoupling of alkyne or alkene might be a challenge in this reaction . To the best of our knowledge, enantioselective reductive coupling of alkynes and cyclic enones to β-alkenyl cyclic ketones is the only one example reported by Cheng’s group in 2011 .…”