Photoinduced Merging with Copper‐ or Nickel‐Catalyzed 1,4‐Cyanoalkylarylation of 1,3‐Enynes to Access Multiple Functionalizatized Allenes in Batch and Continuous Flow

Abstract

Comprehensive SummaryA three‐component reaction of 1,3‐enynes and cyclobutanone oxime esters in the presence of aryl boronic acids or organozinc reagents via the photoredox/copper or photoredox/nickel catalysis has been established. This redox‐neutral 1,4‐cyanoalkylarylation reaction has demonstrated mild condition, high catalytic reactivity and wide functional group compatibility, allowing access to a variety of functionalized tetra‐substituted allene derivatives with high chemo‐ and regioselectivity. Moreover, using photocatalytic continuous flow technique to promote this process would result in increased yields (70% in flow vs. 61% in batch), reduced reaction times (7 min in flow vs. 6 h in batch), and easy scale‐up (upgrade to gram scale), showcasing its potential as a synthetic platform.