86186-47-2Relevant academic research and scientific papers
TfOH-catalyzed intramolecular alkyne-ketone metathesis leading to highly substituted five-membered cyclic enones
Jin, Tienan,Yang, Fan,Liu, Chunli,Yamamoto, Yoshinori
scheme or table, p. 3533 - 3535 (2009/12/02)
The intramolecular carbocyclization of tethered alkynyl ketones to five-membered cyclic enones is shown to be catalyzed by trifluoromethanesulfonic acid in MeOH, proceeding in good to excellent yields and with high selectivities.
Selective mono- and 1,2-difunctionalisation of cyclopentene derivatives via Mg and Cu intermediates
Despotopoulou, Christina,Bauer, Richard C.,Krasovskiy, Arkady,Mayer, Peter,Stryker, Jeffrey M.,Knochel, Paul
experimental part, p. 2499 - 2506 (2009/04/11)
A single Br/Mg exchange of 1,2-dibromocyclopentene with iPrMgCl-LiCl provides the corresponding β-bromocyclopentenylmagnesium reagent, which can then be reacted with various electrophiles (yields: 65-82%). In the presence of a secondary alkylmagnesium halide and Li2CuCl4 (2 mol%), these 2-bromoalkenylmagnesium compounds undergo bromine substitution and can then further react with electrophiles to give 1,2-difunctionalised cyclopentenes (63-79%). The mechanism of this process is discussed.
SCOPE AND STEREOCHEMICAL COURSE OF THE (TRIMETHYLSILYL)CYCLOPENTENE ANNULATION
Danheiser, Rick, L.,Carini, David, J.,Fink, David M.,Basak, Ajoy
, p. 935 - 948 (2007/10/02)
A new, regiospecific annulation approach to highly substituted 5-membered carbocycles has been developed.The "TMS-cyclopentene annulation" involves the reaction of (trimethylsilyl)allenes with electrondeficient alkenes and alkynes in the presence of titanium tetrachloride to afford, in a single step, a functionalized and highly substituted TMS-cyclopentene derivative.Annulations employing α, β-unsaturated ketones proceed stereoselectively via suprafacial addition to the enone.Some useful transformations of the annulation products are also described; for example, treatment with K2CO3-methanol or HF in acetonitrile effects isomerization and desilylation yielding α, β-unsaturated ketones.
