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

Comprehensive Summary A 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. We reported a 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, providing a variety of functionalized tetra‐substituted allenes with high chemo‐ and regioselectivities. 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 (up to gram scale).