A new, highly stereoselective approach to pyrrolidines via overall 5-endo-trig cyclisations of homoallylic tosylamides
作者:Andrew D. Jones、David W. Knight
DOI:10.1039/cc9960000915
日期:——
Iodocyclisations of E-homoallylic tosylamides 7 lead to excellent yields of either 2,5-trans-or 2,5-cis-3-iodopyrrolidines (10 or 11), depending upon the reaction conditions.
Palladium- and Ruthenium-Catalyzed Cycloisomerization of Enynamides and Enynhydrazides: A Rapid Approach to Diverse Azacyclic Frameworks
作者:P. Ross Walker、Craig D. Campbell、Abid Suleman、Greg Carr、Edward A. Anderson
DOI:10.1002/anie.201304186
日期:2013.8.26
I want to ride my azacycle: The title reaction of enynamides affords a wide diversity of azacycles. The reactions are high‐yielding, highly stereoselective, and proceed rapidly under mild reaction conditions. Equivalent transformations using enynhydrazides offer new routes to pyrazole and indazole scaffolds. Boc=tert‐butoxycarbonyl, EWG=electron‐withdrawing group, Ns=4‐nitrobenzenesulfonyl, Ts=4‐toluenesulfonyl
Stereospecific Aminative Cyclizations Triggered by Intermolecular Aza‐Prilezhaev Alkene Aziridination
作者:Matthew J. S. Smith、Wenbin Tu、Craig M. Robertson、John F. Bower
DOI:10.1002/anie.202312797
日期:2023.11.27
acidic reaction conditions (TFA), deprotection of BocNR(OSO2R) reagents triggers intermolecular aminative cyclizations of alkenes equipped with pendant nucleophiles. The processes are predicated on a sequence of stereospecific intermolecular aza-Prilezhaev aziridination followed by stereospecific opening by the pendant nucleophile.
Ring-closing metathesis of ene-ynamide, which has alkene and ynamide moieties in a molecule, using a second-generation ruthenium carbene complex produced nitrogen-containing heterocycles, which have a dienamide moiety, in high yields. Diels-Alder reaction of the cyclized product with dienophile proceeded smoothly to give an indole or quinoline derivative in high yield. (c) 2006 Elsevier Ltd. All rights reserved.
Zirconium-Mediated Intramolecular Ester Transfer Reaction: Synthesis of α-Substituted γ-Aminobutyric Acid (GABA) Derivatives
[GRAPHIC]The zirconium-mediated intramolecular ester transfer reaction of N-alkenyl carbamate derivatives proceeded to give a-substituted gamma-aminobutyric acid (GABA) derivatives in good to excellent yields. Quenching experiments of the reaction mixture with iodine or 02 indicated the presence of a cyclopropane intermediate. The resulting iodide was converted to 2-substituted pyrrolidine-3-carboxylate and/or alpha-alkylidene-gamma-aminobutyric acid derivatives in a stereospecific manner.