A Gold Carbene Manifold to Prepare Fused γ‐Lactams by Oxidative Cyclisation of Ynamides.

Sánchez‐Cantalejo, Fernando; Priest, Joshua D.; Davies, Paul W.

Gold‐catalysed oxidative cyclisation reactions of ynamides offer great promise in γ‐lactam synthesis but are limited by preferential over‐oxidation to form α‐keto imides. Evaluating the factors that might limit N‐cyclisation pathways led to effective gold‐catalysed conditions that allow access to different fused γ‐lactams on changing the ynamide N‐substituent and accommodate previously incompatible substitution patterns. New and efficient methods for the synthesis of functionalised 3‐aryl indoles and cyclohepta[c]pyrrol‐1‐one derivatives are presented. These conditions illustrate the complementarity of gold catalysis to other metals. OxidativeN‐cyclisations of ynamides provide efficient access to a variety of fused γ‐lactams including oxindoles and cyclohepta[c]pyrrol‐1‐one derivatives. A model is proposed to rationalise the reactivity challenges and show how previously dominant over‐oxidation pathways can be overcome to access the desirable reactivity patterns of gold carbenes.

GOLD carbenes; YNAMIDES; OXIDATION; NITROGEN; GOLD catalysts

Chemistry - A European Journal, 2018, Vol 24, Issue 65, p17215

0947-6539

Academic Journal

10.1002/chem.201804378