A Scalable and Metal-Free Synthesis of Indazoles from 2-Aminophenones and In Situ Generated De-Boc-Protected O-Mesitylsulfonyl Hydroxylamine Derivatives
Alkyne Aminopalladation/Heck and Suzuki Cascades: An Approach to Tetrasubstituted Enamines
作者:Finn J. Geffers、Florens R. Kurth、Peter G. Jones、Daniel B. Werz
DOI:10.1002/chem.202103567
日期:2021.10.25
Internal alkynes have been used in combination with tosylamides and the Narasaka leaving group to form tetra(hetero)substituted enamines in an aminopalladationcascade reaction. The cascade was terminated either intramolecularly by a Heck reaction or intermolecularly in a Suzuki-type reaction with a boronic acid.
Pyrrolidines and Piperidines by Ligand-Enabled Aza-Heck Cyclizations and Cascades of <i>N</i>
-(Pentafluorobenzoyloxy)carbamates
作者:Ian R. Hazelden、Rafaela C. Carmona、Thomas Langer、Paul G. Pringle、John F. Bower
DOI:10.1002/anie.201801109
日期:2018.4.23
Ligand‐enabled aza‐Heck cyclizations and cascades of N‐(pentafluorobenzoyloxy)carbamates are described. These studies encompass the first examples of efficient non‐biased 6‐exo aza‐Heck cyclizations. The methodology provides direct and flexible access to carbamate protected pyrrolidines and piperidines.
Complex Polyheterocycles and the Stereochemical Reassignment of Pileamartine A via Aza-Heck Triggered Aryl C–H Functionalization Cascades
作者:Benjamin T. Jones、Javier García-Cárceles、Lewis Caiger、Ian R. Hazelden、Richard J. Lewis、Thomas Langer、John F. Bower
DOI:10.1021/jacs.1c08615
日期:2021.9.29
N-polyheterocycles can be accessed via intramolecular Pd(0)-catalyzed alkene 1,2-aminoarylation reactions. The method uses N-(pentafluorobenzoyloxy)carbamates as the initiating motif, and this allows aza-Heck-type alkene amino-palladation in advance of C–H palladation of the aromatic component. The chemistry is showcased in the first total synthesis of the complex alkaloid (+)-pileamartine A, which has resulted in
Osmium-Catalyzed Vicinal Oxyamination of Alkenes by <i>N</i>-(4-Toluenesulfonyloxy)carbamates
作者:Masruri、Anthony C. Willis、Malcolm D. McLeod
DOI:10.1021/jo301372y
日期:2012.10.5
N-(4-Toluenesulfonyloxy)carbamates based on a range of common amine protecting groups serve as preformed nitrogen sources in the intermolecular osmium-catalyzedoxyamination reaction of a variety of mono-, di-, and trisubstituted alkenes. The reactions occur with low catalyst loadings and good yields and afford high regioselectivity for unsymmetrically substituted alkenes.
A novel and efficient Fe‐catalyzed direct C−H amination (NH2) of arenes is reported using a new redox‐active aminating reagent. The reaction is simple, and can be performed under air, mild, and redox‐neutral conditions. This protocol has a broad substrate scope and could be used in the late‐stage modification of bioactive compounds. Mechanistic studies demonstrate that a radical pathway could be involved