Montmorillonite K 10 (clay) catalyzed hydrolysis of aryl-substituted α,β-difluoroallyl alcohols leading to (Z)-α-fluoro-β-aryl-substituted acrylaldehydes
摘要:
Aryl-substituted alpha,beta-difluoroallyl alcohols 1 were readily hydrolyzed in the presence of a catalytic amount of montmorillonite K 10 (clay) in hexane at reflux temperature for 1 h to give the corresponding (Z)-alpha-fluoro-beta-aryl-substituted acrylaldehydes 2 in good yields. (C) 1999 Elsevier Science Ltd. All rights reserved.
Reaction of β-fluorovinamidinium salt with Grignard reagents. Facile and efficient route to (Z)-α-fluoro-α,β-unsaturated aldehydes
作者:Hiroki Yamanaka、Yasumasa Odani、Takashi Ishihara、John T Gupton
DOI:10.1016/s0040-4039(98)01459-2
日期:1998.9
β-Fluorovinamidinium salt (1) reacted cleanly with a variety of Grignard reagents in tetrahydrofuran at room temperature, followed by acid workup, to produce the corresponding (Z)-α-fluoro-α,β-unsaturated aldehydes (3) in good to excellent yields.
An Efficient and General Entry to (<i>Z</i>)-<i>α</i>-Fluoro-<i>β</i>-substituted Acrylaldehydes Based on the Coupling Reaction of<i>α</i>-Fluoro-<i>β</i>-amino Acrylaldehydes with Organolithium Reagents
of polyfluoroalkenyl tosylates (1) with dialkylamines in the presence of triethylamine and a catalytic amount (10 mol%) of tetrabutylammonium fluoride (TBAF), reacted smoothly with various organolithiumreagents at −78 °C for 0.5 h, followed by hydrolysis with 10% hydrochloric acid at room temperature for 1 h to afford the corresponding (Z)-α-fluoro-β-substituted acrylaldehydes (3) via allylic rearrangement
Stereoselective Construction of Fluorinated Quaternary Stereogenic Centers via an Organocatalytic Asymmetric <i>exo</i>-Selective Diels–Alder Reaction in the Presence of Water
作者:Bojan P. Bondzić、Konstantinos Daskalakis、Tohru Taniguchi、Kenji Monde、Yujiro Hayashi
DOI:10.1021/acs.orglett.2c03043
日期:2022.10.14
A catalytic, asymmetric Diels–Alderreaction of α-fluoro α,β-unsaturated aldehydes and cyclopentadiene was developed using diarylprolinol silyl ether as an organocatalyst. The reaction proceeds in toluene with trifluoroacetic acid as an additive (condition A). Perchloric acid salt of diarylprolinol silyl ether also promotes the reaction using water as a reaction medium (condition B). In both cases
Montmorillonite K 10 (clay) catalyzed hydrolysis of aryl-substituted α,β-difluoroallyl alcohols leading to (Z)-α-fluoro-β-aryl-substituted acrylaldehydes
Aryl-substituted alpha,beta-difluoroallyl alcohols 1 were readily hydrolyzed in the presence of a catalytic amount of montmorillonite K 10 (clay) in hexane at reflux temperature for 1 h to give the corresponding (Z)-alpha-fluoro-beta-aryl-substituted acrylaldehydes 2 in good yields. (C) 1999 Elsevier Science Ltd. All rights reserved.