52457-01-9Relevant academic research and scientific papers
Multicomponent reactions of methyl substituted all-cis tetrafluorocyclohexane aldehydes
Bykova, Tetiana,Al-Maharik, Nawaf,Slawin, Alexandra M. Z.,O'Hagan, David
, p. 1117 - 1123 (2016)
This paper reports the preparation of methyl substituted all-cis tetrafluorocyclohexanes prepared from a Birch reduction of benzoic acid, worked up with a methyl iodide quench. The resultant methylcyclohexadiene carboxylic acid was reduced to the alcohol,
Non-Cryogenic, Ammonia-Free Reduction of Aryl Compounds
-
, (2022/03/31)
A method of reducing an aromatic ring or a cyclic, allylic ether in a compound includes preparing a reaction mixture including a compound including an aromatic moiety or a cyclic, allylic ether moiety, an alkali metal, and either ethylenediamine, diethylenetriamine, triethylenetetramine, or a combination thereof, in an ether solvent; and reacting the reaction mixture at from ?20° C. to 30° C. for a time sufficient to reduce a double bond in the aromatic moiety to a single bond or to reduce the cyclic, allylic ether moiety.
Catalytic Enantioselective Birch–Heck Sequence for the Synthesis of Phenanthridinone Derivatives with an All-Carbon Quaternary Stereocenter
Sexton, Mary,Malachowski, William P.,Yap, Glenn P. A.,Rachii, Diana,Feldman, Greg,Krasley, Andrew T.,Chen, Zhilin,Tran, My Anh,Wiley, Kalyn,Matei, Alexandra,Petersen, Samantha,Tien, Sabrina Tran
, p. 1154 - 1172 (2022/01/20)
Novel phenanthridinone analogues with an all-carbon quaternary stereocenter have been enantioselectively synthesized using the Birch–Heck sequence. Flat phenanthridinone structures have extensive bioactivity but consequently also suffer from poor therapeutic selectivity. The addition of a quaternary center to the phenanthridinone skeleton has the potential to generate more complex analogues with improved selectivity. Unfortunately, no general synthetic pathway to such derivatives exists. Herein we report a four-step process that transforms inexpensive benzoic acid into 22 different quaternary carbon-containing phenanthridinone analogues with a variety of substituents on all three rings: alkyl groups at the quaternary center; methyl, methoxymethyl, or para-methoxybenzyl on the amide nitrogen; and halogen and methyl substituents on the aryl ring. Good to very good enantioselectivity was demonstrated in the key intramolecular desymmetrizing Mizoroki–Heck reaction. Transformations of the Heck reaction products into molecules with potentially greater therapeutic relevance were also accomplished.
The Cyclohexa-2,5-dienyl Group as a Placeholder for Hydrogen: Organocatalytic Michael Addition of an Acetaldehyde Surrogate
Chen, Weiqiang,Fang, Huaquan,Xie, Kaixue,Oestreich, Martin
supporting information, p. 15126 - 15129 (2020/10/23)
An aldehyde with a cyclohexa-2,5-dienyl group in the α-position is introduced as a storable surrogate of highly reactive acetaldehyde. The cyclohexa-2,5-dienyl unit is compatible with an enantioselective Michael addition to nitroalkenes promoted by a Haya
Metal-Free Transfer Hydroiodination of C-C Multiple Bonds
Chen, Weiqiang,Walker, Johannes C. L.,Oestreich, Martin
supporting information, p. 1135 - 1140 (2019/01/11)
The design and a gram-scale synthesis of a bench-stable cyclohexa-1,4-diene-based surrogate of gaseous hydrogen iodide are described. By initiation with a moderately strong Br?nsted acid, hydrogen iodide is transferred from the surrogate onto C-C multiple bonds such as alkynes and allenes without the involvement of free hydrogen iodide. The surrogate fragments into toluene and ethylene, easy-to-remove volatile waste. This hydroiodination reaction avoids precarious handling of hydrogen iodide or hydroiodic acid. By this, a broad range of previously unknown or difficult-to-prepare vinyl iodides can be accessed in stereocontrolled fashion.
Metal-Free Transfer Hydrobromination of C-C Triple Bonds
Chen, Weiqiang,Oestreich, Martin
supporting information, p. 4531 - 4534 (2019/06/27)
A transfer hydrobromination of C-C triple bonds inititated by Br?nsted acids is reported. Hydrogen bromide is released stepwise from a bench-stable cyclohexa-1,4-diene-based surrogate, generating biphenyl and ethylene as waste. A range of vinyl bromides was prepared from terminal and internal, mainly acceptor-substituted alkynes with good functional-group tolerance.
Synthesis of Unzipping Polyester and a Study of its Photochemistry
Joo, Wontae,Wang, Wade,Mesch, Ryan,Matsuzawa, Kensuke,Liu, Di,Willson, C. Grant
supporting information, p. 14736 - 14741 (2019/10/11)
Preparation of an unzipping polyester is reported. The monomer was prepared from benzoic acid in a four-step sequence. Step growth polymerization of the monomer provides the target polymer. Efficient depolymerization upon irradiation at 254 nm was confirm
Functionalized Allyl Aryl Ether Synthesis from Benzoic Acids Using a Dearomatization and Decarboxylative Allylation Approach
Hsieh, Cheng-En,Jiang, Yu-Min,Chou, Chih-Ming
supporting information, p. 653 - 665 (2019/01/24)
A strategy toward the preparation of substituted allyl aryl ethers from benzoic acids via a dearomatization and decarboxylative allylation (DcA) reaction is presented. The benzoic acids undergo a dearomatization to give alkylated 2,5-cyclohexadienyl ketoesters which are subjected to a palladium-catalyzed DcA reaction, providing a variety of functionalized allyl aryl ethers. In addition, the combination of a resonance stabilized DcA reaction with a Claisen rearrangement for the synthesis of multisubstituted phenols and applying to dihydroplicatin B derivative synthesis is also presented.
Rapid Access to Ortho-Alkylated Vinylarenes from Aromatic Acids by Dearomatization and Tandem Decarboxylative C-H Olefination/Rearomatization
Tsai, Hung-Chang,Huang, Yen-Hsiang,Chou, Chih-Ming
supporting information, p. 1328 - 1332 (2018/03/09)
A two-step straightforward method for the preparation of ortho-alkylated vinylarenes from readily available benzoic acids is described. The synthetic route involves the dearomatization of benzoic acids by Birch reduction providing alkylated cyclohexa-2,5-dienyl-1-carboxylic acids. The diene subsequently undergoes a decarboxylative C-H olefination followed by rearomatization to deliver ortho-alkylated vinylarene. Mechanistic studies suggest that a Pd/Ag bimetallic catalytic system is important in the tandem decarboxylative C-H olefination/rearomatization step.
Synthesis of Highly Substituted Arenes via Cyclohexadiene-Alkene C-H Cross Coupling and Aromatization
Bhunia, Anup,Studer, Armido
, p. 1213 - 1217 (2018/02/14)
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 ?-alkylation followed by a Pd-catalyzed decarboxylative β-alkenylation with subsequent aromatization resulting in an overall three-fold ipso-para-ortho functionalization of readily accessed benzoic acid derivatives. Efficient synthesis of various alkyl-alkenylarenes under mild conditions in moderate to excellent yields is presented.
