853955-93-8

Upstream product

• 90646-75-6 ethyl 2,4-dimethyl-4-pentenoate 
• 1483-82-5 phenylethynyl chloride 
• 908125-52-0 2,4-dimethyl-2-phenylethynyl-pent-4-enoic acid ethyl ester 

Downstream Products

• 908124-98-1 C₂₂H₂₄O 
• 853956-02-2 N-(2,4-dimethyl-2-phenylethynyl-pent-4-enyl)-4-methyl-benzenesulfonamide 
• 908124-95-8 tert-butyl-(2,4-dimethyl-2-phenylethynyl-pent-4-enyloxy)-dimethyl-silane 

Relevant academic research and scientific papers

Au- and Pt-catalyzed cycloisomerizations of 1,5-enynes to cyclohexadienes with a broad alkyne scope

We describe the development of gold- and platinum-catalyzed cycloisomerizations of 1,5-enynes. This catalytic process displays a wide alkyne scope and furnishes a range of highly functionalized 1,4- and 1,3-cyclohexadienes. In the case of 1-siloxy-1-yne-5-enes, the reactions are efficiently catalyzed by AuCl (1 mol %) at ambient temperature to afford siloxy cyclohexadienes or the corresponding 1,2- and 1,3-cyclohexenones upon subsequent protodesilylation. We propose that the reaction proceeds via a novel mechanism involving a series of 1,2-alkyl shifts. Elucidation of this unusual reaction mechanism enabled us, in turn, to significantly expand the scope of the cycloisomerization by incorporation of a quaternary center at the C(3) position of the enyne. Indeed, we established that PtCl2 (5 mol %) efficiently catalyzed the cycloisomerizations of 1,5-enynes containing terminal, internal, and arene-conjugated alkynes. Since a variety of 1,5-enynes are readily accessible, the cycloisomerization provides a rapid approach to a wide range of highy substituted cyclohexadienes for many subsequent synthetic applications.

Gold-catalyzed assembly of heterobicyclic systems

We have described an efficient gold-catalyzed double cyclization of 1,5-enynes to afford a range of heterobicyclic compounds, including oxabicylclo[3.2.1]octenes, azabicyclo[3.2.1]octenes, oxaspiro[5.4]decene, azaspiro[5.4]decene, oxaspiro[5.5]undecene, o