Synthesis of Highly Substituted Arenes via Cyclohexadiene–Alkene C–H Cross Coupling and Aromatization
作者:Anup Bhunia、Armido Studer
DOI:10.1021/acscatal.8b00083
日期:2018.2.2
The development of a cross-coupling method for the regioselective β-alkenylation of 2,5-cyclohexadiene carboxylic acid derivatives to form ortho-alkenylarenes through in situ decarboxylation and aromatization is described. The carboxylic acid functionality is used as a traceless directing group for efficient and mild β-alkenylation. The modular sequence comprises a reductive Birch α-alkylation, ionic
Regioselective Arene Functionalization: Simple Substitution of Carboxylate by Alkyl Groups
作者:Tobias Krüger、Katja Vorndran、Torsten Linker
DOI:10.1002/chem.200901774
日期:2009.11.9
from toluic and naphthoic acids, the carboxylate group was conveniently substituted by alkyl halides by Birch reduction and subsequent decarbonylation. The method is characterized by inexpensive starting materials and reagents, and methylation of arenes was realized. Besides simple alkyl substituents, the scope of arene functionalization was extended by benzyl, fluoro, amino, and ester groups. We were
Regioselective Threefold Aromatic Substitution of Benzoic Acid Derivatives by Dearomatization, Regioselective Functionalization, and Rearomatization
作者:Eva Koch、Armido Studer
DOI:10.1002/anie.201300259
日期:2013.4.26
Ipso, meta, and para: Benzoic acid derivatives can be highly regioselectively substituted at the ipso, meta, and para positions. The reaction sequence comprises an alkylative Birchreduction, a 4‐alkylation, a palladium‐catalyzed γ‐arylation, and an oxidative rearomatization (see scheme). All the reactions are robust and experimentally easy to conduct.
Walk on the same side! The title reaction occurs by means of highly stereospecific 1,3‐metal migration. The starting carboxylic acids are readily prepared by Birch reduction, and the developed protocol provides an efficient route to enantiomerically pure 5‐arylated‐1,3‐cyclohexadiene derivatives (see scheme).
Diastereoselective Hydroformylation of 2,5-Cyclohexadienyl-1-carbinols with Catalytic Amounts of a Reversibly Bound Directing Group
作者:Ippei Usui、Kenichi Nomura、Bernhard Breit
DOI:10.1021/ol1028546
日期:2011.2.18
A phosphinite plays a role as a reversiblybounddirectinggroup for the regio- and diastereoselectivehydroformylation of 2,5-cyclohexadienyl-1-carbinols. Of the two alkene functions only one was functionalized through hydroformylation to form a synthetically attractive quaternary carbon center leaving the second alkene function for potential further functionalization.