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
through synergistic Pd/Cu-catalyzed dynamic kinetic asymmetricallenylation with racemic allenylic esters. The protocol is suitable for a wide range of substrates including the challenging allenylic esters with less sterically bulky substituents and provided chiral allenylic products bearing 1,3-nonadjacent stereocenters with high levels of enantio- and diastereoselectivities (up to >20:1 dr and >99% ee)
Rhodium Complex-Catalyzed Cycloisomerization of Allenenes: Exo and Endo Cyclization Depending on the Auxiliary Ligands
作者:Tatsuya Makino、Kenji Itoh
DOI:10.1021/jo035551x
日期:2004.1.1
having an exo-alkylidene moiety. In this cycloisomerization, (E)- and (Z)-allenenes are transformed stereospecifically to the corresponding cyclic (E)- and (Z)-1,4-dienes, respectively. On the other hand, the reactions under carbon monoxide atmosphere exclusively afford seven-membered-ring products through an endo-mode cyclization. The unusual cyclization involves an allylic C−H activation process. The
Highly Regio- and Stereoselective Synthesis of Alkylidenecyclopropanes via Ru(II)-Pheox Catalyzed Asymmetric Inter- and Intramolecular Cyclopropanation of Allenes
An efficient protocol for the synthesis of optically active alkylidenecyclopropanes (ACPs) via the Ru(II)-Pheox catalyzed asymmetric cyclopropanation of allenes has been established. This catalytic system proceeded with high regioselectivity to give the ACP products in high yield with high diastereoselectivity (up to 99/1) and enantioselectivity (up to 99% ee).
[3]Dendralene Synthesis: Rhodium(III)-Catalyzed Alkenyl CH Activation and Coupling Reaction with Allenyl Carbinol Carbonate
作者:Honggen Wang、Bernhard Beiring、Da-Gang Yu、Karl D. Collins、Frank Glorius
DOI:10.1002/anie.201306754
日期:2013.11.18
[3]DendrAl(l)ene! A new synthesis of [3]dendralenes is based on a RhIII‐catalyzed alkenyl CH activation and coupling reaction with allenyl carbinol carbonates (see scheme; DG=directing group). A variety of [3]dendralenes with diverse substitution patterns are accessible with good efficiency. The reaction is highly stereoselective and compatible with different directing groups and numerous functional