2-difunctionalized benzenes, the sites other than its formal triple bond remain silent in typical benzyne transformations. An unprecedented aryne 1,2,3,5-tetrasubstitution was realized from 3-silylbenzyne and aryl allyl sulfoxide, the mechanistic pathway of which includes a regioselective aryne insertion into the S═O bond, a [3,6]-sigmatropic rearrangement, and a thermal aromatic 1,3-silyl migration cascade.
A bromine-radical mediated three-component reaction comprising allenes, electron-deficient alkenes and allyl bromides: facile synthesis of 2-bromo-1,7-dienes
作者:Takashi Kippo、Ilhyong Ryu
DOI:10.1039/c4cc01597e
日期:——
A bromine-radical mediated three-component coupling reaction was effectively achieved by the use of allenes, electron-deficientalkenes, and allyl bromides and led to the synthesis of 2-bromo-1,7-dienes in good to high yields. This protocol was extended to the three-component process using alkylidenecyclopropane, which gave 2-bromo-1,8-diene along with alkylidenecyclopentane.
4-Alkyl- and 4-Cinnamylglutamic Acid Analogues Are Potent GluR5 Kainate Receptor Agonists
作者:Concepción Pedregal、Iván Collado、Ana Escribano、Jesús Ezquerra、Carmen Domínguez、Ana I. Mateo、Almudena Rubio、S. Richard Baker、John Goldsworthy、Rajender K. Kamboj、Barbara A. Ballyk、Ken Hoo、David Bleakman
DOI:10.1021/jm9911682
日期:2000.5.1
Enantiomerically pure (2S,4R)-4-substituted glutamic acids were prepared and tested for homomeric GluR5 and GluR6 kainate subtype receptor affinity. Some of the 4-cinnamyl analogues showed high selectivity and potency (K(i) < 25 nM) for the GluR5 receptors. The greatest selectivity and potency were achieved with the 3-(2-naphthyl)prop-2-enyl compound. This compound, LY339434, has negligible activity
which otherwise are essentially reluctant towards F‐nucleoplilic addition, now readily participate in this fluoroallylation reaction. Furthermore, this strategy provides an elegant example for the generation, as well as functionalization, of α‐CF3‐substituted benzylic radical intermediates using cheap and readily available starting materials.
to produce unisolable allylchromium species which add efficiently to aldehydes or ketones with high degree of stereo- and chemoselectivity. Particularly, high threo selectivity is observed in the reaction of aldehydes and 1-bromo-2-butene and is ascribed to a chair-like six-membered transition state. Simple reduction of allylic and benzylic halides produces biallyls and bibenzyls, while gem-dibromocyclopropanes