Front Cover Picture: Gold(I)/Chiral Rh(III) Lewis Acid Relay Catalysis Enables Asymmetric Synthesis of Spiroketals and Spiroaminals (Adv. Synth. Catal. 21/2018)

The front cover picture, provided by Qiang Kang and co-workers, illustrates an efficient bimetallic gold(I)/chiral rhodium(III) Lewis acid asymmetric relay catalysis. The gold(I)-catalyzed 5-exo-dig intramolecular cyclization of alkynyl alcohol or amide can afford an active electron-rich cyclic intermediate, which is in situ trapped by β,γ-unsaturated α-keto esters activated by a chiral Rh(III) Lewis acid catalyst. The corresponding chiral spiroketals and spiroaminals were obtained in high yields with good stereoselectivities. Details can be found in the communication on pages 4031–4036 (J. Gong, Q. Wan, Q. Kang, Adv. Synth. Catal. 2018, 360, 4031–4036; DOI: 10.1002/adsc.201800492).