Isolable and Readily Handled Halophosphonium Pre-reagents for Hydro- and Deuteriohalogenation
作者:Florian T. Schevenels、Minxing Shen、Scott A. Snyder
DOI:10.1021/jacs.6b12653
日期:2017.5.10
and acid-sensitive moieties, particularly polyenes prone to cyclization. The process is also challenging when conducted on a small scale, and moreover, methods for the addition of their deuterated counterparts typically require special techniques, especially when control of stoichiometry is required. Herein is described a readily synthesized and handled reagent class which can accomplish the controlled
Cu(I)-Catalyzed, α-Selective, Allylic Alkylation Reactions between Phosphorothioate Esters and Organomagnesium Reagents
作者:Andrew M. Lauer、Farzeen Mahmud、Jimmy Wu
DOI:10.1021/ja202954b
日期:2011.6.15
of allylic alkylation reactions involving hard nucleophiles remains a significant challenge and continues to be an active area of research. The lack of general methods in which α-alkylation is favored underscores the need for the development of new processes for achieving this type of selectivity. We report that Cu(I) catalyzes the allylic substitution of phosphorothioate esters with excellent α-regioselectivity
Lewis Acid-Promoted Intermolecular Acetal-Initiated Cationic Polyene Cyclizations
作者:Yu-Jun Zhao、Shu-Sin Chng、Teck-Peng Loh
DOI:10.1021/ja067660+
日期:2007.1.1
This paper describes a highly efficient intermolecular biomimeticpolyenecyclization method using acetal as initiators. Both good yield and asymmetricinduction were obtained.
本文介绍了一种以乙缩醛为引发剂的高效分子间仿生多烯环化方法。获得了良好的产量和不对称诱导。
Et<sub>2</sub>SBr⋅SbCl<sub>5</sub>Br: An Effective Reagent for Direct Bromonium-Induced Polyene Cyclizations
作者:Scott A. Snyder、Daniel S. Treitler
DOI:10.1002/anie.200903834
日期:2009.10.5
It's all about reactivity: Although bromonium‐induced cation–π cyclizations are commonly utilized by nature to fashion six‐membered rings from a diverse set of polyene precursors, no general laboratory method exists that can achieve the same breadth of substrate scope. An easily synthesized and handled reagent is described (see scheme) that is capable of directly, broadly, and rapidly effecting such
Enantioselective, Lewis Base-Catalyzed Sulfenocyclization of Polyenes
作者:Zhonglin Tao、Kevin A. Robb、Kuo Zhao、Scott E. Denmark
DOI:10.1021/jacs.8b01660
日期:2018.3.14
Homogeranylarenes and ortho-geranylphenols undergo polycyclization in good yield, diastereoselectivity, and enantioselectivity. The stereodetermining step is the generation of an enantiomericallyenrichedthiiraniumion from a terminal alkene and a sulfenylating agent in the presence of a chiral Lewis basic catalyst. The use of hexafluoroisopropyl alcohol as the solvent is crucial to obtain good yields