35 research outputs found
Allenyl Azide Cycloaddition Chemistry. Synthesis of Pyrrolidine-Containing Bicycles and Tricycles via the Possible Intermediacy of Azatrimethylenemethane Species
Thermolysis of 5-azidoallenes bearing a C(1) methyl group and either an aryl ring or an alkene on C(1) furnishes tricyclic (from the aryl substrates) or bicyclic (from the alkenyl substrates) pyrrolidine products following formal H−CN addition across an intermediate imine. High levels of diastereoselectivity are observed in all cases studied. This reaction cascade presumably passes through unobserved triazoline and azatrimethylenemethane diyl intermediates en route to product
Allenyl Azide Cycloaddition Chemistry. Synthesis of Pyrrolidine-Containing Bicycles and Tricycles via the Possible Intermediacy of Azatrimethylenemethane Species
Thermolysis of 5-azidoallenes bearing a C(1) methyl group and either an aryl ring or an alkene on C(1) furnishes tricyclic (from the aryl substrates) or bicyclic (from the alkenyl substrates) pyrrolidine products following formal H−CN addition across an intermediate imine. High levels of diastereoselectivity are observed in all cases studied. This reaction cascade presumably passes through unobserved triazoline and azatrimethylenemethane diyl intermediates en route to product
Allenyl Azide Cycloaddition Chemistry. Synthesis of Annelated Indoles from 2-(Allenyl)phenyl Azide Substrates
Thermolysis of 2-(allenyl)phenyl azides leads to a cascade cyclization sequence furnishing both C(2)−C(3) and N−C(2) cyclopentannelated
indoles
Ellagitannin Chemistry. Studies on the Stability and Reactivity of 2,4-HHDP-Containing Glucopyranose Systems
The synthesis of a 2,4-HHDP containing glucopyranose ellagitannin model system has been
achieved. Attempts to prepare a related target bearing a 1,6 bridge led instead to the discovery of
a likely strain-driven tautomerization to cyclohexadienone intermediates
Allenyl Azide Cycloaddition Chemistry. Synthesis of Annelated Indoles from 2-(Allenyl)phenyl Azide Substrates
Thermolysis of 2-(allenyl)phenyl azides leads to a cascade cyclization sequence furnishing both C(2)−C(3) and N−C(2) cyclopentannelated
indoles
Allenyl Azide Cycloaddition Chemistry. Synthesis of Annelated Indoles from 2-(Allenyl)phenyl Azide Substrates
Thermolysis of 2-(allenyl)phenyl azides leads to a cascade cyclization sequence furnishing both C(2)−C(3) and N−C(2) cyclopentannelated
indoles
Allenyl Azide Cycloaddition Chemistry: Exploration of the Scope and Mechanism of Cyclopentennelated Dihydropyrrole Synthesis through Azatrimethylenemethane Intermediates
Detailed studies of the thermal conversion of 1-azidohepta-3,4,6-trienes into cyclopentennelated dihydropyrroles are presented. High levels of diastereoselectivity and regioselectivity are documented. A mechanistic proposal that accounts for all of the diverse results is developed through the use of density functional calculations. These calculations provide support for the intervention of unexpected mechanistic subtleties, such as the planarity of an azatrimethylenemethane diyl intermediate and an apparent Woodward−Hoffmann-type electrocyclization of a five-atom diyl array
Allenyl Azide Cycloaddition Chemistry: Exploration of the Scope and Mechanism of Cyclopentennelated Dihydropyrrole Synthesis through Azatrimethylenemethane Intermediates
Detailed studies of the thermal conversion of 1-azidohepta-3,4,6-trienes into cyclopentennelated dihydropyrroles are presented. High levels of diastereoselectivity and regioselectivity are documented. A mechanistic proposal that accounts for all of the diverse results is developed through the use of density functional calculations. These calculations provide support for the intervention of unexpected mechanistic subtleties, such as the planarity of an azatrimethylenemethane diyl intermediate and an apparent Woodward−Hoffmann-type electrocyclization of a five-atom diyl array
Allenyl Azide Cycloaddition Chemistry: Exploration of the Scope and Mechanism of Cyclopentennelated Dihydropyrrole Synthesis through Azatrimethylenemethane Intermediates
Detailed studies of the thermal conversion of 1-azidohepta-3,4,6-trienes into cyclopentennelated dihydropyrroles are presented. High levels of diastereoselectivity and regioselectivity are documented. A mechanistic proposal that accounts for all of the diverse results is developed through the use of density functional calculations. These calculations provide support for the intervention of unexpected mechanistic subtleties, such as the planarity of an azatrimethylenemethane diyl intermediate and an apparent Woodward−Hoffmann-type electrocyclization of a five-atom diyl array
Allenyl Azide Cycloaddition Chemistry: Exploration of the Scope and Mechanism of Cyclopentennelated Dihydropyrrole Synthesis through Azatrimethylenemethane Intermediates
Detailed studies of the thermal conversion of 1-azidohepta-3,4,6-trienes into cyclopentennelated dihydropyrroles are presented. High levels of diastereoselectivity and regioselectivity are documented. A mechanistic proposal that accounts for all of the diverse results is developed through the use of density functional calculations. These calculations provide support for the intervention of unexpected mechanistic subtleties, such as the planarity of an azatrimethylenemethane diyl intermediate and an apparent Woodward−Hoffmann-type electrocyclization of a five-atom diyl array
