Au-Catalyzed Asymmetric Polyene Cyclization and Its Application in the Total Synthesis of (+)-2-Ketoferruginol, (+)-Fleuryinol B, (+)-Salviol, and (-)-Erythroxylisin A.

A catalytic asymmetric 1,3-acyloxy shift/polyene cyclization cascade has been achieved with good enantioselectivities under the catalysis of the chiral Au(I) reagent. The synthetic utility of this method has been showcased by the catalytic asymmetric total syntheses of (+)-2-ketoferruginol, (+)-fleuryinol B, and (+)-salviol. Notably, the first enantioselective total synthesis of (-)-erythroxylisin A has also been realized in 15 steps.

InI-catalyzed polyene cyclization of allenes and its application in the total synthesis of seven abietane-type diterpenoids.

A novel polyene cyclization using the allene group as the initiator has been successfully developed. This methodology provides an efficient strategy for the construction of an abietane-type tricyclic skeleton with a functionalizable C2-C3 double bond and features a wide substrate scope and excellent stereoselectivities. Potential utility of this approach has been well demonstrated by the collective total synthesis of seven abietane-type diterpenoids.

Au(I)-Catalyzed Cyclization/Semipinacol Rearrangement Reaction of Allenes to Construct Quaternary Carbon-Containing Scaffolds.

The development of methods toward the construction of quaternary carbon centers has been a hot topic in recent years. In this work, an Au(I)-catalyzed intramolecular cyclization/semipinacol rearrangement of allene-containing allylic silyl ether was developed to provide a direct strategy for the construction of multisubstituted cyclohexene-type compounds with a quaternary carbon center in moderate to good yields. In particular, this method provides an alternative synthetic strategy for the construction of a multisubstituted spirocyclo[4.

Facile access to diverse all-carbon quaternary center containing spirobicycles by exploring a tandem Castro-Stephens coupling/acyloxy shift/cyclization/semipinacol rearrangement sequence.

Efficient combination of two or more reactions into a practically useful purification free sequence is of great significance for the achievement of structural complexity and diversity, and an important approach for the development of new synthetic strategies that are industrially step-economic and environmentally friendly. In this work, a facile and efficient method for the construction of highly functionalized spirocyclo[4.5]decane derivatives containing a synthetically challenging quaternary carbon center has been successfully developed through the realization of a tandem Castro-Stephens coupling/1,3-acyloxy shift/cyclization/semipinacol rearrangement sequence.