Intramolecular Silanoxy-Michael\nReactions with Pendant\nNitroalkenes: Racemic and Enantioselective

We present the first racemic and\nscalemic examples of di-<i>tert</i>-butyl silanoxy-Michael\nadditions. Our operationally\nsimple protocol is selective for nitro-olefins and simply involves\nstirring the substrate with an appropriate hydrogen-bond donor catalyst\nwithout any special precautions to exclude air or moisture. For each\nsubstrate examined, we have developed complementary protocols that\noptimize yield and enantioselectivity. Our reactions scale well, and\nthe products are valuable intermediates for further transformations,\nincluding for the preparation of enantioenriched vicinal amino alcohols.