31689-39-1Relevant academic research and scientific papers
Palladium-Catalyzed Decarboxylative γ-Olefination of 2,5-Cyclohexadiene-1-carboxylic Acid Derivatives with Vinyl Halides
Chang, Chi-Hao,Chou, Chih-Ming
, p. 1949 - 1952 (2018)
This study explores a Pd-catalyzed decarboxylative Heck-type Csp3-Csp2 coupling reaction of 2,5-cyclohexadiene-1-carboxylic acid derivatives with vinyl halides to provide γ-olefination products. The olefinated 1,3-cyclohexadienes can be further oxidized to produce meta-alkylated stilbene derivatives. Additionally, the conjugated diene products can also undergo a Diels-Alder reaction to produce a bicyclo[2.2.2]octadiene framework.
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.
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.
Diastereoselective hydroformylation of 2,5-cyclohexadienyl-1-carbinols with catalytic amounts of a reversibly bound directing group
Usui, Ippei,Nomura, Kenichi,Breit, Bernhard
supporting information; experimental part, p. 612 - 615 (2011/04/26)
A phosphinite plays a role as a reversibly bound directing group for the regio-and diastereoselective hydroformylation of 2,5-cyclohexadienyl-1- carbinols. Of the two alkene functions only one was functionalized through hydroformylation to form a syntheti
Simple two-step ipso substitution of aromatic carboxylic acids by alkyl halides
Vorndran, Katja,Linker, Torsten
, p. 2489 - 2491 (2007/10/03)
Methyl-substituted arenes can be synthesized with high regioselectivity in only two steps through formal exchange of an aromatic carboxylic acid function with an alkyl substituent. The results obtained with toluic acid illustrate that good to very good yields can be obtained from inexpensive reagents (see scheme).
Unique carbon-carbon bond homolysis in 3-alkylcyclohexa-1,4-dienyl-3-carboxylic acid radicals
Baguley, Paul A.,Binmore, Gavin,Milne, Aynsley,Walton, John C.
, p. 2199 - 2200 (2007/10/03)
3-Substituted cyclohexadienyl radicals generated by hydrogen abstraction from 3-alkylcyclohexa-1,4-diene-3-carboxylic acids readily fragment to produce alkyl radicals and benzoic acid; suitably functionalised alkyl groups cyclize in moderate yields.
