Organo-Cation Catalyzed Asymmetric Homo/Heterodialkylation of Bisoxindoles: Construction of Vicinal All-Carbon Quaternary Stereocenters and Total Synthesis of (-)-Chimonanthidine.

A novel chiral spirocyclic amide (SPA)-derived triazolium organocatalyst has been designed and demonstrated to effect asymmetric homo- and heterodialkylations of various bisoxindoles, enabling enantioselective construction of vicinal all-carbon quaternary stereocenters. These reactions feature excellent enantio- and diastereoselectivities (up to 99% ee and >20:1 dr) as well as good to high yields (up to 89% over two steps). As an application of this methodology, the first asymmetric total synthesis of (-)-chimonanthidine has been achieved.

Improved synthesis of 8-oxabicyclo[3.2.1]octanes via tandem C-H oxidation/oxa-[3,3] Cope rearrangement/aldol cyclization.

A tandem C-H oxidation/oxa-[3,3] Cope rearrangement/aldol reaction of allylic silylethers promoted by TBF(tempo oxoammonium tetrafluoroborate)/ZnBr has been successfully developed allowing the efficient construction of 8-oxabicyclo[3.2.1]octanes and their analogs with a wide substrate scope.

Catalytic Asymmetric Cascade Using Spiro-Pyrrolidine Organocatalyst: Efficient Construction of Hydrophenanthridine Derivatives.

A newly developed SPD (spiro-pyrrolidine) organocatalyst has been demonstrated to enable an asymmetric aza-Michael/Michael/aldol cyclization cascade, in which two six-membered rings (B/C) and three stereocenters have been constructed in a catalytic one-step process. It is so far the most efficient method for construction of hydrophenanthridine derivatives featuring high enantioselectivity. The trans- or cis-fused B/C-rings can be selectively assembled in a substrate-controlled manner.

[Mutation screening of VHL gene in a Chinese family with nonsyndromic pheochromocytoma].

Objective: To detect the VHL gene mutations in a Chinese family with nonsyndromic pheochromocytoma.

Methods: Mutations of VHL gene were detected in a Chinese family with nonsyndromic pheochromocytoma. Five patients and fifteen relatives were involved in this study.