Benzyne-induced ring opening reaction of thiiranes. Efficient synthesis of phenyl vinyl sulfides
作者:Juzo Nakayama、Satoshi Takeue、Masamatsu Hoshino
DOI:10.1016/s0040-4039(01)81261-2
日期:1984.1
A series of thiiranes react with benzyne to provide an efficient synthesis of phenyl vinyl sulfides. The reaction is stereospecific, thus producing cis-(phenylthio)-stilbene from cis-2,3-diphenylthiirane and trans-(phenylthio)stilbene from trans-2,3-diphenylthiirane.
N 2 from a primary alkanediazonium ion predominantly takes place concomitantly with participation of a C-H bond of the neighboring 1-alkyl group to form a nonclassical cationic species with a three-center two-electron bonding, while the loss of N 2 from a secondary alkanediazonium ion occurs spontaneously to form a secondary carbocation. Solvent effects (CHCl 3 vs AcOH) are explained in terms of lower
Novel aryne Diels-Alderreactions with functionalized acyclic dienes are reported. These give useful cis-substituted dihydronaphthalene building blocks in good yield which are not easily accessible via other means, as demonstrated in the synthesis of sertraline. The first asymmetric aryne cycloaddition with an acyclic diene is also reported, giving excellent diastereoselectivities with Oppolzer's sultam
The structure of a constrained bicyclic chiral derivatizing agent (CDA), 1,2,3,4-tetrahydro-1,4-epoxynaphthalene-1-carboxylic acid, THENA 1, was modified by replacing both exo-methylene protons with deuterium atoms. The modified CDA, THENA-d2 2, could be used to assign the absolute configuration of chiralsecondaryalcohols with good reliability. Compared with THENA, the multiplicity of the methylene
受限的双环手性衍生剂(CDA)1,2,3,4-四氢-1,4-环氧萘-1-羧酸THENA 1的结构是通过用氘原子取代两个外亚甲基质子来进行的。改进的CDA THENA- d 2 2可用于分配具有良好可靠性的手性仲醇的绝对构型。与THENA相比,THENA - d 2衍生物的1 H NMR光谱中的亚甲基质子信号的复杂性更低,因此新的CDA为数据解释提供了更简单的NMR光谱。
Diels–Alder reactivity of pyrano[3,4-b]indol-3-ones, stable, synthetic equivalents of indole-2,3-quinodimethanes
作者:Christopher J. Moody
DOI:10.1039/c39840000925
日期:——
Pyrano[3,4-b]indol-3-ones (5), syntheticequivalents of indole-2,3-quinodimethanes, undergo Deils–Alder reaction with acetylenes and with benzyne to give carbazoles and benzo[b]carbozoles respectively.
吡喃并[3,4- b ]吲哚-3-酮(5)是吲哚-2,3-喹二甲烷的合成等价物,与乙炔和苯并炔进行Deils-Alder反应,分别得到咔唑和苯并[ b ]咔唑。