81763-00-0Relevant academic research and scientific papers
Radical Aza-Cyclization of α-Imino-oxy Acids for Synthesis of Alkene-Containing N-Heterocycles via Dual Cobaloxime and Photoredox Catalysis
Tu, Jia-Lin,Liu, Jia-Li,Tang, Wan,Su, Ma,Liu, Feng
supporting information, p. 1222 - 1226 (2020/02/15)
Nitrogen-containing heterocycles are prevalent in both naturally and synthetically bioactive molecules. We report herein an unprecedented protocol for radical aza-cyclization of α-imino-oxy acids with pendant alkenes via synergistic photoredox and cobaloxime catalysis. With or without alkenes as the intermolecular cross-coupling partners, the transformation provides a variety of corresponding alkene-containing dihydropyrrole products in satisfactory yields. In the presence of external alkenes, the tandem reaction generates E-selective coupling products with excellent chemo- and stereoselectivity.
Features and applications of [Rh(CO)2Cl]2-catalyzed alkylations of unsymmetrical allylic substrates
Ashfeld, Brandon L.,Miller, Kenneth A.,Smith, Anna J.,Tran, Kristy,Martin, Stephen F.
, p. 9018 - 9031 (2008/03/13)
(Chemical Equation Presented) A novel regio- and stereoselective [Rh(CO)2Cl]2-catalyzed allylic alkylation of unsymmetrical allylic carbonates was discovered. The regioselectivity of the reaction favors product ratios in which substitution occurs at the carbon bearing the leaving group. When an enantiomerically enriched carbonate (≥99% ee) was examined, the Rh(I)-catalyzed allylic alkylation proceeded stereoselectively to provide the alkylation product with retention of absolute stereochemistry (98% ee). To establish the scope of the [Rh(CO)2Cl]2-catalyzed allylic alkylation, a variety of carbon and heteroatom nucleophiles were examined and the results described. As an application of the Rh(I)-catalyzed allylic alkylation, a series of novel domino reactions have been developed that couple the unique regio- and stereoselective [Rh(CO)2Cl]2- catalyzed alkylation of allylic trifluoroacetates with an intramolecular Pauson-Khand annulation, a cycloisomerization, or a [5+2] cycloaddition. A unique aspect of the method described is the use of a single catalyst to effect sequential transformations in which the catalytic activity is moderated simply by controlling the reaction temperature. Implementation of such processes provides a rapid and efficient entry to a variety of bicyclic carbon skeletons from simple precursors.
SYNTHESIS OF STABLE ANALOGUES OF TXA2
Evans, Elizabeth H.,Hewson, Alan T.,March, Lorraine A.,Nowell, Ian W.,Wadsworth, Alan H.
, p. 137 - 150 (2007/10/02)
Intramolecular aldol condensations and intramolecular Lewis acid-catalysed alkylations are used in approaches to substituted bicyclononanes and bicyclooctanes, specifically the oxo esters ( 7 ), ( 8 ), and ( 9 ).A ring expansion to a cycloheptane derivative is observed on treatment of the cyclopentyl derivative ( 18 ) with acid, and the bicyclodecane and bicyclononane derivatives ( 34 ) and ( 36 ) are obtained from the prenyl derivatives ( 30 ) and ( 35 ) respectively.The oxo esters ( 7 ), (8 ), and ( 9 ) are converted into the stable TXA2 analogues ( 10 ), ( 11 ), and ( 12 ) respectively, by a series of reactions which involve stereospecific functionalisation of their ketone and ester groups.
INTRAMOLECULAR LEWIS ACID CATALYSED ALKYLATIONS
Evans, Elizabeth H.,Hewson, Alan T.,Hadsworth, Alan H.
, p. 243 - 248 (2007/10/02)
Lewis acid catalysed cyclisations of enol derivatives leading to both bridged and fused bicyclic systems are described.
