Ruthenium-Catalyzed Asymmetric [2 + 2] Cycloadditions between Chiral Acyl Camphorsultam-Substituted Alkynes and Bicyclic Alkenes
作者:Jordan Goodreid、Karine Villeneuve、Emily Carlson、William Tam
DOI:10.1021/jo501594g
日期:2014.11.7
Ruthenium-catalyzedasymmetric [2 + 2] cycloadditionsbetweenchiralacyl camphorsultam-functionalized alkynes and bicyclicalkenes were examined, providing adducts with complete exo stereoselectivity in good overall yield and enantioselectivity (up to 99% and 166:1, respectively), as well as appreciable diastereoselectivity (up to 163:1). The diastereoselectivity showed dependence on the solvent and
Iron-Catalyzed Cross-Coupling Reactions between a Bicyclic Alkenyl Triflate and Grignard Reagents
作者:Paul Le Marquand、Gavin C. Tsui、John C. C. Whitney、William Tam
DOI:10.1021/jo801384e
日期:2008.10.3
Fe-catalyzed cross-couplingreactions between a bicyclic alkenyl triflate and Grignard reagents were investigated. Under the optimized reaction conditions, various 2-substituted bicyclic alkenes were synthesized in moderate to excellent yields (52-93%). This method provided an efficient route for the synthesis of 2-substituted bicyclic alkenes with secondary alkyl groups which cannot be synthesized
(NBD–QC) photoswitching molecules. These molecules feature either linearly conjugated or cross-conjugated pi-electron systems. Upon photoisomerization, the UV-vis absorptionspectra of the molecules revealed a strong blue shift in the QC-form, with a photoisomerizationquantumyield close to 80% for the cross-conjugated systems. In contrast, a strong intrinsic emission (up to Φf = 49%) for the linearly conjugated
Selective Mono- and 1,2-Difunctionalisation of Cyclopentene Derivatives via Mg and Cu Intermediates
作者:Christina Despotopoulou、Richard C. Bauer、Arkady Krasovskiy、Peter Mayer、Jeffrey M. Stryker、Paul Knochel
DOI:10.1002/chem.200701431
日期:2008.3.7
A single Br/Mg exchange of 1,2-dibromocyclopentene with iPrMgCl LiCl provides the corresponding beta-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
Synthesis of cyclopentadiene derivatives by retro-Diels–Alder reaction of norbornadiene derivatives
作者:Erdin Dalkılıç、Arif Daştan
DOI:10.1016/j.tet.2015.02.023
日期:2015.4
Synthesis of cyclopentadiene derivatives starting from norbornadiene was investigated using dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate. The products obtained were either cyclopentadienes or diazines depending on the substituents. The driving force for the formation of these products was discussed in terms of electronic effects.