We report herein the synthesis of complex molecules containing furopyran cores through a gold(I)-catalyzed hetero Diels-Alder cascade reaction. During this process, the diene and the dienophile are produced concomitantly by the action of a single catalyst from a single starting material. Moreover, six bonds, four heterocycles and four controlled stereogenic centers are formed in a one-step operation. DFT calculations provide the mechanistic basis of this unprecedented reaction.

The synthesis of benzosultams has been achieved through a gold(I)-catalyzed ammonium formation strategy. Starting from easily available N-(2-alkynyl)phenylsulfonyl azetidine derivatives, a cyclization reaction generated a spiroammonium gold intermediate which was ring-opened by nucleophilic alcohol or indole. This new methodology is compatible with large variation on the substrates and nucleophiles, and allowed to form benzosultams in high yield (18-98%, 20 examples). This strategy also allowed the preparation of benzosultam analogs via iododeauration and subsequent cross-coupling reactions.

Suzuki–Miyaura cross-coupling reactions of aryl/vinyl sulfonates/halides with various boron species were performed using an easily available trans -dichlorobis(XPhos)palladium(II) precatalyst. Under microwave assistance, more than 30 coupling products were obtained with yields ranging from 23 to 99%, including the synthesis of two bioactive compounds, dubamine and tamoxifen. A mechanistic investigation of the Suzuki–Miyaura reaction was conducted notably by nuclear magnetic resonance (NMR) and high-resolution mass spectroscopy, revealing the nature of the active Pd 0 species and of the reducing entity.