Huifei Wang

Synthesis of Polysubstituted Pyridines via a One-Pot Metal-Free Strategy.

An efficient strategy for the one-pot synthesis of polysubstituted pyridines via a cascade reaction from aldehydes, phosphorus ylides, and propargyl azide is reported. The reaction sequence involves a Wittig reaction, a Staudinger reaction, an aza-Wittig reaction, a 6π-3-azatriene electrocyclization, and a 1,3-H shift. This protocol provides quick access to the polysubstituted pyridines from readily available substrates in good to excellent yields.

Asymmetric Total Synthesis of (−)-Aspidophylline A

An asymmetric total synthesis of (-)-aspidophylline A has been accomplished. The key transformations include an asymmetric hydride transfer hydrogenation of an α,β-acetylenic ketone and a cationic gold(I)-catalyzed 6-exo-dig cyclization involving an alkynylindole/aminal formation cascade, which enables stereoselective establishment of the requisite quaternary carbon center.

Total Synthesis of the Diterpenoid (+)-Harringtonolide

Described herein is the first asymmetric total synthesis of (+)-harringtonolide, a natural diterpenoid with an unusual tropone imbedded in a cagelike framework. The key transformations include an intramolecular Diels-Alder reaction and a rhodium-complex-catalyzed intramolecular [3+2] cycloaddition to install the tetracyclic core as well as a highly efficient tropone formation.

Divergent Total Syntheses of (−)-Daphnilongeranin B and (−)-Daphenylline

(-)-Daphnilongeranin B and (-)-daphenylline are two hexacyclic Daphniphyllum alkaloids, each containing a complex cagelike backbone. Described herein are the first asymmetric total synthesis of (-)-daphnilongeranin B and a bioinspired synthesis of (-)-daphenylline with an unusual E ring embedded in a cagelike framework. The key features include an intermolecular [3+2] cycloaddition, a late-stage aldol cyclization to install the F ring of daphnilongeranin B, and a bioinspired cationic rearrangement leading to the tetrasubstituted benzene ring of daphenylline.

A One-Pot Synthesis of Dibenzofurans from 6-Diazo-2-cyclohexenones

A novel and efficient protocol for the rapid construction of dibenzofuran motifs from 6-diazo-2-cyclohexenone and ortho-haloiodobenzene has been developed. The process involves one-pot Pd-catalyzed cross-coupling/aromatization and Cu-catalyzed Ullmann coupling.

Collective Total Synthesis of (−)-Lundurines A–C

A collective asymmetric total synthesis of lundurines A-C using l-pyroglutamic acid derived from the chiral pool is described. The key steps include a tandem reductive amination/lactamization sequence to introduce the pyrrolidinone ring, a palladium-catalyzed intramolecular direct C-H vinylation of indole to construct the crucial polyhydroazocine ring, and a Lewis acid promoted formal [3 + 2] cycloaddition/N2 extrusion process to install the polysubstituted cyclopropyl ring.

Formal Synthesis of (±)-Aplykurodinone-1 through a Hetero-Pauson–Khand Cycloaddition Approach

The tricyclic intermediate 2 has been synthesized in eight steps from known compound 6 in 20% overall yield. As such, this constitutes a highly efficient formal synthesis of (±)-aplykurodinone-1. This synthesis features a unique, one-pot, intramolecular hetero-Pauson-Khand reaction (h-PKR)/desilylation sequence to expeditiously construct the tricyclic framework, providing valuable insights for expanding the scope and boundaries of h-PKR.

New reactivity of ethynyl benziodoxolone: modulating iron-catalyzed dehydration of propargyl alcohols

A practical method for dehydration of alcohols, mainly propargyl alcohols, promoted by silyl-EBX is reported, which represents the first example of using only a catalytic amount of silyl-EBX since its discovery. A broad range of aryl propargyl alcohols proceeded smoothly and gave the dehydration products in good to excellent yields. Preliminary mechanistic studies ruled out the radical pathways and supported an E1 process for this reaction. The carbon–carbon triple bond and the lactone moiety within the EBX molecule may have played an important role in the reaction.