Selective ortho C-H Cyanoalkylation of (Diacetoxyiodo)arenes through [3,3]-Sigmatropic Rearrangement

摘要

We herein report a robust catalyst-free cross-coupling between ArI(OAc)(2) and -stannyl nitriles, aided by TMSOTf. The transformation introduces a cyanoalkyl group to the ortho position of ArI(OAc)(2) and simultaneously reduces the aryl iodine(III) to iodide, thus providing -(2-iodoaryl) nitrile as the product. This transformation could be completed within 5min at -78 degrees C and features superb functional-group tolerance and efficient scalability. DFT calculations indicate that the formation of a ketenimine(aryl)iodonium intermediate and subsequent [3,3]-sigmatropic rearrangement are involved as key steps.