Described herein is a flexible modular approach to planar chiral carba-paracyclophanes via the stepwise assembly of two distinct side arms and the aromatic core followed by ring-closing olefin metathesis. Planar chirality is induced by one chiral sulfinyl group by forming a hydrogen bond to the phenol in the aromatic unit.
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
The preparations and some properties of mixed aryl-thienyl oligomers and polymers
作者:Andrew Pelter、Ieuan Jenkins、D.Elfyn Jones
DOI:10.1016/s0040-4020(97)00629-7
日期:1997.7
The syntheses by transition metal coupling reactions of a large number of oligomers constructed from benzene and thiophene rings are described. The first use of arylcadmium chlorides for such coupling reactions is reported. The routes chosen allow for rational variation in the modes of linkage, the substitution and the proportions of the two units. The benzene and thiophene rings are always joined
Simple Reagents for Direct Halonium-Induced Polyene Cyclizations
作者:Scott A. Snyder、Daniel S. Treitler、Alexandria P. Brucks
DOI:10.1021/ja106813s
日期:2010.10.13
Although there are many reagent combinations that can initiate polyenecyclizations, simple electrophilic halogen sources have not yet proven broadly effective as promoters of such processes. Herein is described a readily prepared and stable class of reagents capable of effecting such transformations for a wide range of electron-rich and -deficient terpenes derived from geraniol, farnesol, and nerol
尽管有许多试剂组合可以引发多烯环化,但尚未证明简单的亲电子卤素源作为此类过程的促进剂广泛有效。本文描述了一类易于制备且稳定的试剂,能够对源自香叶醇、法呢醇和橙花醇的各种富电子和缺电子萜烯进行此类转化,从而能够有效合成多种复杂的氯- 、含溴和含碘的多环骨架。迄今为止的努力已导致抗 HIV 天然产物 Peyssonol A 的第一个外消旋实验室全合成和结构修订,以及 peyssonoic acid A 的有效和简洁的首次全合成。他们还允许正式的外消旋全合成 aplysin- 20、萝莉莉德、K-76、和 Stemodin 将通过通常比以前的努力更短、产量更高且更具环保意识的途径来实现。还描述了使用该试剂类的手性形式进行对映选择性烯烃卤化的初步尝试。