Catalytic Asymmetric Nitroso‐Diels–Alder Reaction with Acyclic Dienes

Bigger, bulkier, better: Catalytic asymmetric nitroso-Diels–Alder reactions of nitrosopyridines with silyloxydienes lead to adducts with excellent enantioselectivities (see scheme). The bulk of the silyl group (TMS=trimethylsilyl, TIPS=triisopropylsilyl) forces the diene to adopt an s-cis configuration in favor of the typical concerted [4+2] cycloaddition. The Diels–Alder adducts can then be converted into protected amino alcohols.