use of amino alcohols as alkylating agents was demonstrated. The catalyst tolerates numerous functional groups, including hydrogenation‐sensitive examples. Compared to many other alcohol‐based amine alkylation methods, where a stoichiometric amount of base is required, our Cr‐based catalyst system gives yields higher than 90 % for various alkyl amines with a catalytic amount of base. Our study indicates
Evolution of a Synthetic Strategy: Total Synthesis of (±)-Welwitindolinone A Isonitrile
作者:Sarah E. Reisman、Joseph M. Ready、Matthew M. Weiss、Atsushi Hasuoka、Makoto Hirata、Kazuhiko Tamaki、Timo V. Ovaska、Catherine J. Smith、John L. Wood
DOI:10.1021/ja076663z
日期:2008.2.1
An efficient and highly stereoselective total synthesis of the natural product (+/-)-welwitindolinone A isonitrile (1) is described. The bicyclo[4.2.0]octane core of 1 was established by a regio- and diastereoselective [2+2] ketene cycloaddition. The C12 quaternary center and vicinal stereogenic chlorine were installed in a single operation with excellent stereocontrol via a chloronium ion mediated
Synthesis of N−H Bearing Imidazolidinones and Dihydroimidazolones Using Aza‐Heck Cyclizations
作者:Feiyang Xu、Scott A. Shuler、Donald A. Watson
DOI:10.1002/anie.201806295
日期:2018.9.10
The synthesis of unsaturated, unprotected imidazolidinones via an aza‐Heck reaction is described. This palladium‐catalyzed process allows for the cyclization of N‐phenoxy ureas onto pendant alkenes. The reaction has broad functional group tolerance, can be applied to complex ring topologies, and can be used to directly prepare mono‐ and bis‐unprotected imidazolidinones. By addition of Bu4NI, dihydroimidazolones
Preparation of Heterocyclic Amines by an Oxidative Amination of Zinc Organometallics Mediated by CuI: A New Oxidative Cycloamination for the Preparation of Annulated Indole Derivatives
作者:Marcel Kienle、Andreas J. Wagner、Cora Dunst、Paul Knochel
DOI:10.1002/asia.201000367
日期:2011.2.1
Functionalized heterocyclic zinc reagents are easily aminated by an oxidativeaminationreaction of zinc amidocuprates prepared from various lithium amides. For the oxidation step, PhI(OAc)2 proved to be the best reagent. The required heterocyclic zinc organometallics can be prepared either by direct metalation, by magnesium insertion in the presence of ZnCl2, or by transmetalation of a suitable magnesium
Domino Palladium-Catalyzed Heck-Intermolecular Direct Arylation Reactions
作者:Olivier René、David Lapointe、Keith Fagnou
DOI:10.1021/ol901799p
日期:2009.10.15
A dominopalladium-catalyzed Heck-intermolecular directarylation reaction has been developed, giving access to a variety of dihydrobenzofurans, indolines, and oxindoles. A variety of sulfur-containing heterocycles such as thiazoles, thiophenes, and benzothiophene can be employed as the directarylation coupling partner in yields up to 99%.