Highly diastereo- and branched-selective rearrangement of substituted -alloc--allyl ynamides.

An auto-tandem catalytic, branched-selective rearrangement of substituted -alloc--allyl ynamides was developed. This reaction provides ready access to complex quaternary nitrile products with vinylogous stereocentres in excellent diastereoselectivity, including contiguous all-carbon quaternary centres. The stereochemical outcome is determined a Pd(0) catalysed dipolar ketenimine aza-Claisen rearrangement and computational studies exemplify the key role ligand geometry plays.