Rh(III)-catalyzed Intra- and Intermolecular 3,4-Difunctionalization of 1,3-Dienes via Rh(III)-π-allyl Amidation with 1,4,2-Dioxazolones.

Abstract

We herein report a modular strategy, which enables Rh(III)-catalyzed diastereoselective 3,4-amino oxygenation and diamination of 1,3-dienes using different O- and N-nucleophiles in combination with readily available 3-substituted 1,4,2-dioxazolones (78 examples, 37-91% yield). Previous attempts to functionalize the internal double bond rested on the use of plain alcoholic solvents as nucleophilic coupling partners thus dramatically limiting the scope of this transformation. We have now identified hexafluoroisopropanol as a non-nucleophilic solvent which allows the use of diverse nucleophiles and greatly expands the scope, including an unprecedented amino hydroxylation to selectively install valuable, unprotected β-amino alcohols across 1,3-dienes. Moreover, various elaborate alcohols prove to be compatible providing unique access to complex organic molecules. Finally, this method is employed in a series of intramolecular reactions to deliver valuable nitrogen heterocycles as well as γ- and δ-lactones.