67759-79-9Relevant academic research and scientific papers
Chemoselectivity for Alkene Cleavage by Palladium-Catalyzed Intramolecular Diazo Group Transfer from Azide to Alkene
Frost, Grant B.,Mittelstaedt, Michaela N.,Douglas, Christopher J.
supporting information, p. 1727 - 1732 (2019/01/09)
Alkenes can be cleaved by means of the (3+2) cycloaddition and subsequent cycloreversion of 1,3-dipoles, classically ozone (O3), but the azide (R?N3) variant is rare. Chemoselectivity for these azide to alkene diazo group transfers (DGT) is typically disfavored, thus limiting their synthetic utility. Herein, this work discloses a palladium-catalyzed intramolecular azide to alkene DGT, which grants chemoselectivity over competing aziridination. The data support a catalytic cycloreversion mechanism distinct from other known metal-catalyzed azide/alkene reactions: nitrenoid/metalloradical and (3+2) cycloadditions. Kinetics experiments reveal an unusual mechanistic profile in which the catalyst is not operative during the rate-controlling step, rather, it is active during the product-determining step. Catalytic DGT was used to synthesize N-heterocyclic quinazolinones, a medicinally relevant structural core. We also report on the competing aziridination and subsequent ring expansion to another N-heterocyclic core structure of interest, benzodiazepinones.
Rotational features of carbon-nitrogen bonds in axially chiral o-tert- butyl anilides and related molecules. Potential substrates for the 'prochiral auxiliary' approach to asymmetric synthesis
Curran, Dennis P.,Hale, Gregory R.,Geib, Steven J.,Balog, Aaron,Cass, Quezia B.,Degani, Ana Luiza G.,Hernandes, Marcelo Z.,Freitas, Luiz Carlos G.
, p. 3955 - 3975 (2007/10/03)
A new strategy for asymmetric induction termed the 'prochiral auxiliary' approach is introduced. Reactions of acylating agents with prochiral N- methyl-o-tert-butyl aniline provide anilides that are axially chiral by virtue of restricted rotation about th
Studies on the Benzoxazine Series. 2- Preparation and 1H and 13C NMR Structural Study of Some Substituted 1,2-Dihydro-4H-3,1-benzoxazines
Neuvonen, Kari,Pohtola, Riitta,Pihlaja, Kalevi
, p. 725 - 733 (2007/10/02)
In addition to the parent compounds, nine methyl-substituted 1,2-dihydro-4H-3,1-benzoxazines with and without N-methyl substitution were prepared.The chain tautomer could only be detected in the case of 1,2-dihydro-2-(p-nitrophenyl)-4H-3,1-benzoxazine in
Carbon Dioxide: A Reagent for the Simultaneous Protection of Nucleophilic Centres and the Activation of Alternative Locations to Electrophilic Attack. Prt III. A New Synthetic Method for the ortho-Substitution of N-Monoalkylanilines
Katritzky, Alan R.,Fan, Wei-Qiang,Akutagawa, Kunihiko
, p. 4027 - 4034 (2007/10/02)
N-Methyl- and N-ethyl-aniline are regiospecifically converted into a range of ortho-substituted derivatives, using carbon dioxide both for N-protection and as an intermediate carbanion stabilizing group, and t-butyllithium to lithiate the ortho-carbon atom.The rersulting lithium N-(ortho-substituted-phenyl)-N-methyl- and -N-ethylcarbamates undergo smooth acid-catalysed decarboxylation under mild conditions.No alpha-substituted products were detected.
Alkaloid synthesis via the intramolecular imidate methylide 1,3-dipolar cycloaddition reaction
Smith, Richard,Livinghouse, Tom
, p. 3559 - 3568 (2007/10/02)
A concise synthesis for the neurotoxic physostigmine alkaloid d,l-eserethole is described which relys upon an intramolecular cycloaddition reaction involving a "non-stabilized" imidate methylide and an unactivated alkene. The facility of this cyclization
