Highly Active Au(I) Catalyst for the Intramolecular <i>e</i><i>xo</i>-Hydrofunctionalization of Allenes with Carbon, Nitrogen, and Oxygen Nucleophiles
作者:Zhibin Zhang、Cong Liu、Robert E. Kinder、Xiaoqing Han、Hua Qian、Ross A. Widenhoefer
DOI:10.1021/ja062045r
日期:2006.7.19
Au-catalyzed intramolecularhydroalkoxylation within minutes at room temperature to form the corresponding oxygen heterocycles in good yield with high exo-selectivity. 2-Allenyl indoles underwent Au-catalyzed intramolecular hydroarylation within minutes at room temperature to form 4-vinyl tetrahydrocarbazoles in good yield. Au-catalyzed cyclization of N-allenyl carbamates, allenyl alcohols, and 2-allenyl
Silver-Catalysed Enantioselective Addition of OH and NH Bonds to Allenes: A New Model for Stereoselectivity Based on Noncovalent Interactions
作者:Jannine L. Arbour、Henry S. Rzepa、Julia Contreras-García、Luis A. Adrio、Elena M. Barreiro、King Kuok Mimi Hii
DOI:10.1002/chem.201200547
日期:2012.9.3
complexes to catalyse the enantioselective addition of OH and NHbonds to allenes is demonstrated for the first time by using optically active anionic ligands that were derived from oxophosphorus(V) acids as the sources of chirality. The intramolecular addition of acids, alcohols, and amines to allenes can be achieved with up to 73 % ee. The exploitation of a CH anomeric effect allowed the absolute configuration
precursors. When armed with a methylene phosphine oxide moiety on the stereogenic center adjacent to the nitrogenatom, the corresponding bifunctional carbene ligands give rise to highly enantioselective heterocyclizations. DFT calculations brought some rationalization and highlighted the critical roles played by the phosphine oxide group and the tosylate anion in the asymmetric cyclization of γ-allenols
Enzymatic Bromocyclization of α‐ and γ‐Allenols by Chloroperoxidase from
<i>Curvularia inaequalis</i>
作者:Janne M. Naapuri、Philip K. Wagner、Frank Hollmann、Jan Deska
DOI:10.1002/open.202100236
日期:2022.1
Vanadate-dependent chloroperoxidasefromCurvulariainaequalis catalyzes 5-endo-trig bromocyclizations of α-allenols as well as the 5-exo-trig bromocyclizations of γ-allenols to produce valuable halofunctionalized furans. An aqueous biphasic emulsion, based on either cationic or non-ionic surfactants, acts as reaction medium, and allows effective halogenation reactions utilizing hydrogen peroxide as