Xiao-Xiao Li

Formal Intermolecular [2 + 2] Cycloaddition Reaction of Alleneamides with Alkenes via Gold Catalysis

An efficient method was developed to construct the densely functionalized cyclobutane[corrected] adducts through formal intermolecular cycloaddition of allenamides [corrected] with electron-rich olefins via gold catalysis, in which vinyl ethers/amides and electron-rich styrenes worked very well. In addition, a series of allenamide [corrected] dimerization products were prepared from the same allenamide [corrected] substrates.

Gold Catalyzed Diastereoselective Cascade Allylation/Enyne Cycloisomerization to Construct Densely Functionalized Oxygen Hetereocycles

A new tandem allylation/enyne cycloisomerization reaction was developed to construct densely functionalized oxygen heterocycles with high diastereoselectivities from the intermolecular reaction of allylic acetates with propargylic alcohols via gold catalysis. Terminal and nonterminal propargylic alcohols take different reaction routes either to provide 3-oxa-bicyclo[4.1.0]hept-4-ene derivatives 5 or to give endocyclic rearrangement products 7 and alkoxycyclization adducts 8. Cyclopropanes stereochemistry was mainly determined by allylic substituents.

Highly N2-selective coupling of 1,2,3-triazoles with indole and pyrrole.

Hydrogen-bond mediated coupling of 1,2,3-triazoles to indoles and pyrroles results in N2 selective functionalization of the triazole moiety in moderate to excellent yields. The reaction was tolerant of un-, mono- and disubstituted triazoles and was applied to synthesize tryptophan derived fluorescent amino acids.

Divergent synthetic routes for ring expansion or cyclization from 1,4-allylic diol derivatives via gold(I) catalysis or zinc(II) mediation.

A new efficient method was developed to transform cyclic alkanols into one-carbon higher homologated ketones using various esters as the leaving groups through gold-catalyzed allylic cation-promoted pinacol-type rearrangement. This reaction, coupled with oxy-Cope rearrangement, provided a new strategy to synthesize five-carbon homologated ring ketones. In addition, using ZnBr(2), 2,5-dihydrofuran products were obtained in moderate to good yields via an intramolecular cyclization process.

Gold Catalyzed Carbocyclization of Dienyl Acetates to Construct Mutifunctionalized 3-Vinyl Cyclohexanol Derivatives

A convenient new method was developed to construct six-membered 3-vinylcyclohexanols (and piperidine products) and 6-oxabicyclo[3.2.1]octan-7-one derivatives with high diastereoselectivities from 1,6-dienyl acetates via gold catalysis. The reaction proceeded through the nucleophilic addition of the alkenes onto the allylic cation group via a 6-endo-trig process. The substrates structure affected the configuration orientation of the allylic cation group in a boatlike transition state, which afforded either the trans-cyclohexanols or cis-piperidine derivatives.

CCDC 776682: Experimental Crystal Structure Determination

Related Article: Li-Li Zhu, Ya-Hui Wang, Yu-Xin Zhang, Xiao-Xiao Li, Heng Liu, Zili Chen|2011|J.Org.Chem.|76|441|doi:10.1021/jo1018014