Comparisons of O-acylation and Friedel–Crafts acylation of phenols and acyl chlorides and Fries rearrangement of phenyl esters in trifluoromethanesulfonic acid: effective synthesis of optically active homotyrosines
Reactions involving phenol derivatives and acyl chlorides have to be controlled for competitive O-acylations and C-acylations (Friedel–Crafts acylations and Fries rearrangements) in acidic condition. The extent for these reactions in trifluoromethanesulfonic acid (TfOH), which is used as catalyst and solvent, is examined. Although diluted TfOH was needed for effective O-acylation, concentrated TfOH
Catalytic Enantioselective Synthesis of 2,3-Dihydrobenzo[<i>b</i>]oxepines via Asymmetric Oxetane Opening by Internal Carbon Nucleophiles
作者:Tianyu Zhang、Han Zhuang、Luning Tang、Zhengyu Han、Wengang Guo、Hai Huang、Jianwei Sun
DOI:10.1021/acs.orglett.1c03852
日期:2022.1.14
An intramolecular C–C formation process based on catalytic asymmetric oxetane opening by carbonnucleophiles has been developed, which provides rapid access to a range of valuable enantioenriched 2,3-dihydrobenzo[b]oxepines. With the combination of Sc(OTf)3 and a Box ligand, good chemical efficiency and enantioselectivity were achieved under mild conditions. The products are also useful precursors
已经开发出一种基于碳亲核试剂催化不对称氧杂环丁烷开环的分子内 C-C 形成过程,它可以快速获得一系列有价值的对映体富集的 2,3-二氢苯并[ b ]氧杂环丁烷。Sc(OTf) 3和Box配体的结合,在温和条件下实现了良好的化学效率和对映选择性。该产品也是其他有价值结构的有用前体,例如双环[3.2.2]壬烷衍生物。
XLII.—The variation of phenol coefficients in homologous series of phenols
作者:Charles Edward Coulthard、Joseph Marshall、Frank Lee Pyman
DOI:10.1039/jr9300000280
日期:——
The Mechanisms of the Fries Reaction<sup>1</sup>
作者:Richard Baltzly、Walter S. Ide、Arthur P. Phillips
DOI:10.1021/ja01614a049
日期:1955.5
Synthesis of E-3-Hydroxymethyl-1-methoxy-4-(1′-pentenyl)benzene
作者:Robin G.F. Giles、Ivan R. Green、J. Alexandre X. Pestana
DOI:10.1080/00397919508011471
日期:1995.12
The title compound with exclusively the E-geometry has been synthesized by two independent routes. When this compound was reacted with cerium(IV) ammonium nitrate, it was found that oxidative cyclisation to the corresponding 4-hydroxybenzopyrans did not occur. This further defines the structural parameters required for such oxidative cyclisations.