Syn-Stereocontrolled dihydroxylation of Baylis-Hillman adducts
作者:István E. Markó、Paul R. Giles、Zdenek Janousek、Nigel J. Hindley、Jean-Paul Declercq、Bernard Tinant、Janine Feneau-Dupont、John S. Svendsen
DOI:10.1002/recl.19951140418
日期:——
The hydroxylation of Baylis-Hillmanadducts 1 is shown to proceed with high levels of diastereocontrol. A mechanistic rationale to explain this selectivity is discussed.
DMAP- or imidazole-mediated clean and rapid conversion of cyclic Morita–Baylis–Hillman (MBH) acetates into the corresponding γ-keto allyl phosphonates in 70–93% yields is described herein. This allylic nucleophilic substitution works well with primary and secondary acetates bearing, at the β′-position, linear or branched alkyl groups and aryl groups.
Metal catalyst-free N-allylation/alkylation of imidazole and benzimidazole with Morita–Baylis–Hillman (MBH) alcohols and acetates
作者:Olfa Mhasni、Jalloul Bouajila、Farhat Rezgui
DOI:10.3762/bjoc.19.93
日期:——
substitution of cyclic MBH alcohols and acetates with imidazole or benzimidazole, in toluene at reflux with an azeotropic distillation, was successfully carried out with no catalysts or additives, affording the corresponding N-substituted imidazole derivatives in good yields. On the other hand, in refluxing toluene or methanol, the aza-Michael addition of imidazole onto acyclic MBH alcohols was performed using
The Friedel-Crafts reaction of a wide variety of arenes and heteroarenes was accomplished, in good to excellent yields (50-98%) and with high alpha -regioselectivity, using Morita-Baylis-Hillman acetates. Functionalized conjugated enones were obtained under Bi(OTf)(3) catalysis (10 mol%) in dichloroethane (DCE) at 50 degrees C. (C) 2020 Elsevier Ltd. All rights reserved.
Regioselective<i>S</i>-allylation of thiols with cyclic Baylis–Hillman acetates
An efficient and mild S-allylation of thiols with cyclic Baylis-Hillman acetates with no need of a transition-metal-catalyst or an expensive additive is described. Allyl sulfides are prepared in good to excellent yields (60-97%) and a single regioisomer was observed in all cases.[GRAPHICS].