35519-96-1Relevant articles and documents
Borane-Catalyzed, Chemoselective Reduction and Hydrofunctionalization of Enones Enabled by B-O Transborylation
Nicholson, Kieran,Langer, Thomas,Thomas, Stephen P.
supporting information, p. 2498 - 2504 (2021/04/13)
The use of stoichiometric organoborane reductants in organic synthesis is well established. Here these reagents have been rendered catalytic through an isodesmic B-O/B-H transborylation applied in the borane-catalyzed, chemoselective alkene reduction and formal hydrofunctionalization of enones. The reaction was found to proceed by a 1,4-hydroboration of the enone and B-O/B-H transborylation with HBpin, enabling catalyst turnover. Single-turnover and isotopic labeling experiments supported the proposed mechanism of catalysis with 1,4-hydroboration and B-O/B-H transborylation as key steps.
Stereoselection in Intramolecular Diels-Alder Reactions of 2-Cyano-1-azadienes: Indolizidine and Quinolizidine Synthesis
Tay, Gidget C.,Sizemore, Nicholas,Rychnovsky, Scott D.
supporting information, p. 3050 - 3053 (2016/07/13)
Progress toward understanding the scope and diastereoselectivity of intramolecular Diels-Alder reactions using 2-cyano-1-azadienes is described herein. The resulting cyanoenamine products are underutilized intermediates in organic synthesis. Assembly of the Diels-Alder precursors was achieved using an improved imine condensation/oxidative cyanation protocol. By this method, several highly substituted indolizidine and quinolizidine architectures were constructed. Quantum mechanical DFT calculations at the B3LYP/6-31+G(d) level of theory were performed for these cyclizations and provide insights into the origins of the observed diastereoselectivities.
Cyclization-endoperoxidation cascade reactions of dienes mediated by a pyrylium photoredox catalyst
Gesmundo, Nathan J.,Nicewicz, David A.
supporting information, p. 1272 - 1281 (2014/06/24)
Triarylpyrylium salts were employed as single electron photooxidants to catalyze a cyclization-endoperoxidation cascade of dienes. The transformation is presumed to proceed via the intermediacy of diene cation radicals. The nature of the diene component was investigated in this context to determine the structural requirements necessary for successful reactivity. Several unique endoperoxide structures were synthesized in yields up to 79%.
Preparation of bicyclic 1,2,4-trioxanes from γ,δ-unsaturated ketones
Ramirez, Armando P.,Thomas, Andrew M.,Woerpel
supporting information; experimental part, p. 507 - 510 (2009/08/07)
(Chemical Equation Presented) Treatment of γ,δ-unsaturated ketones with hydrogen peroxide and acid provides a rapid entry into the medicinally important 1,2,4-trioxane structure. Alkene substitution that stabilizes carbocationic intermediates proved to be important for the success of this transformation.
Aluminium triflate-catalysed regioselective cycloisomerisation of non-activated unsaturated oximes
Chaminade, Xavier,Chiba, Shunsuke,Narasaka, Koichi,Dunach, Elisabet
, p. 2384 - 2387 (2008/09/18)
A novel cycloisomerisation of oximes bearing non-activated C-C double bonds occurs in an Al(III)-catalysed reaction. This process leads to 5-, 6- and 7-membered ring oxygen and nitrogen-containing heterocycles in good yields.
Synthesis of Quinolines and 2H-Dihydropyrroles by Nucleophilic Substitution at the Nitrogen Atom of Oxime Derivatives
Kitamura, Mitsuru,Yoshida, Masayuki,Kikuchi, Takashi,Narasaka, Koichi
, p. 2415 - 2426 (2007/10/03)
Isomerization of oxime derivatives was researched in detail to find out the methods for the syn-anti isomerization of O-substituted oximes. Based on these findings were developed simple methods for the preparation of aza-heterocycles from both stereoisomers of oximes. Quinolines were synthesized from β-aryl ketone oximes by treatment with trifluoroacetic anhydride and 4-chloranil. γ,δ-Unsaturated O-methoxyacetyloximes were transformed to 2H-dihydropyrroles by reaction with methoxy-acetic acid.
