5292-23-9Relevant academic research and scientific papers
Ligand-Controlled Regiodivergence in Nickel-Catalyzed Hydroarylation and Hydroalkenylation of Alkenyl Carboxylic Acids**
Deng, Ruohan,Engle, Keary M.,Fu, Yue,Gao, Yang,Li, Zi-Qi,Liu, Peng,Tran, Van T.
supporting information, p. 23306 - 23312 (2020/10/19)
A nickel-catalyzed regiodivergent hydroarylation and hydroalkenylation of unactivated alkenyl carboxylic acids is reported, whereby the ligand environment around the metal center dictates the regiochemical outcome. Markovnikov hydrofunctionalization products are obtained under mild ligand-free conditions, with up to 99 % yield and >20:1 selectivity. Alternatively, anti-Markovnikov products can be accessed with a novel 4,4-disubstituted Pyrox ligand in excellent yield and >20:1 selectivity. Both electronic and steric effects on the ligand contribute to the high yield and selectivity. Mechanistic studies suggest a change in the turnover-limiting and selectivity-determining step induced by the optimal ligand. DFT calculations reveal that in the anti-Markovnikov pathway, repulsion between the ligand and the alkyl group is minimized (by virtue of it being 1° versus 2°) in the rate- and regioselectivity-determining transmetalation transition state.
Exploration of New Biomass-Derived Solvents: Application to Carboxylation Reactions
Gevorgyan, Ashot,Hopmann, Kathrin H.,Bayer, Annette
, p. 2080 - 2088 (2020/02/20)
A range of hitherto unexplored biomass-derived chemicals have been evaluated as new sustainable solvents for a large variety of CO2-based carboxylation reactions. Known biomass-derived solvents (biosolvents) are also included in the study and the results are compared with commonly used solvents for the reactions. Biosolvents can be efficiently applied in a variety of carboxylation reactions, such as Cu-catalyzed carboxylation of organoboranes and organoboronates, metal-catalyzed hydrocarboxylation, borocarboxylation, and other related reactions. For many of these reactions, the use of biosolvents provides comparable or better yields than the commonly used solvents. The best biosolvents identified are the so far unexplored candidates isosorbide dimethyl ether, acetaldehyde diethyl acetal, rose oxide, and eucalyptol, alongside the known biosolvent 2-methyltetrahydrofuran. This strategy was used for the synthesis of the commercial drugs Fenoprofen and Flurbiprofen.
Synthesis of Carboxylic Acids by Palladium-Catalyzed Hydroxycarbonylation
Sang, Rui,Kucmierczyk, Peter,Dühren, Ricarda,Razzaq, Rauf,Dong, Kaiwu,Liu, Jie,Franke, Robert,Jackstell, Ralf,Beller, Matthias
supporting information, p. 14365 - 14373 (2019/09/06)
The synthesis of carboxylic acids is of fundamental importance in the chemical industry and the corresponding products find numerous applications for polymers, cosmetics, pharmaceuticals, agrochemicals, and other manufactured chemicals. Although hydroxycarbonylations of olefins have been known for more than 60 years, currently known catalyst systems for this transformation do not fulfill industrial requirements, for example, stability. Presented herein for the first time is an aqueous-phase protocol that allows conversion of various olefins, including sterically hindered and demanding tetra-, tri-, and 1,1-disubstituted systems, as well as terminal alkenes, into the corresponding carboxylic acids in excellent yields. The outstanding stability of the catalyst system (26 recycling runs in 32 days without measurable loss of activity), is showcased in the preparation of an industrially relevant fatty acid. Key-to-success is the use of a built-in-base ligand under acidic aqueous conditions. This catalytic system is expected to provide a basis for new cost-competitive processes for the industrial production of carboxylic acids.
Two-carbon ring expansion of 1-indanones via insertion of ethylene into carbon-carbon bonds
Xia, Ying,Ochi, Shusuke,Dong, Guangbin
, p. 13038 - 13042 (2019/08/26)
A rhodium-catalyzed direct insertion of ethylene into a relatively unstrained carbon-carbon bond in 1-indanones is reported, which provides a two-carbon ring expansion strategy for preparing seven-membered cyclic ketones. As many 1-indanones are commercially available and ethylene is inexpensive, this strategy simplifies synthesis of benzocycloheptenones that are valuable synthetic intermediates for bioactive compounds but challenging to prepare otherwise. In addition, the reaction is byproduct-free, redox neutral, and tolerant of a wide range of functional groups, which may have implications on unconventional strategic bond disconnections for preparing complex cyclic molecules.
4-Amino-2,1,3-benzothiadiazole as a Removable Bidentate Directing Group for the Pd(II)-Catalyzed Arylation/Oxygenation of sp2/sp3 β-C-H Bonds of Carboxamides
Reddy, Chennakesava,Bisht, Narendra,Parella, Ramarao,Babu, Srinivasarao Arulananda
, p. 12143 - 12168 (2016/12/23)
In this paper, we report 4-amino-2,1,3-benzothiadiazole (ABTD) as a new bidentate directing group for the Pd(II)-catalyzed sp2/sp3 C-H activation/functionalization of various aliphatic/alicyclic/aromatic carboxamide systems. The Pd(II)-catalyzed, ABTD-directed sp3 C-H arylation/acetoxylation of aliphatic- and alicyclic carboxamides afforded the corresponding β-C-H arylated/acetoxylated carboxamides. The Pd(II)-catalyzed, ABTD-directed sp3 C-H arylation of cyclobutanecarboxamide with different aryl iodides afforded the corresponding bis β-C-H arylated cyclobutanecarboxamides having all-cis stereochemistry with a high degree of stereocontrol. The Pd(II)-catalyzed, ABTD-directed arylation/benzylation/acetoxylation/alkoxylation of ortho C(sp2)-H bonds of various benzamides afforded the corresponding ortho C-H arylated/benzylated/oxygenated benzamides. The observed regio- and stereoselectivity in the Pd(II)-catalyzed, ABTD-directed arylation/benzylation of aliphatic/alicyclic carboxamides and benzamides were ascertained from the X-ray structures of representative compounds 5g (bis-β-C(sp3)-H arylated cyclobutanecarboxamide) and 7f (ortho C(sp2)-H arylated benzamide). A brief description on the efficiency, scope, and limitations of bidentate directing group ABTD is reported.
Optimization of a Novel Quinazolinone-Based Series of Transient Receptor Potential A1 (TRPA1) Antagonists Demonstrating Potent in Vivo Activity
Schenkel, Laurie B.,Olivieri, Philip R.,Boezio, Alessandro A.,Deak, Holly L.,Emkey, Renee,Graceffa, Russell F.,Gunaydin, Hakan,Guzman-Perez, Angel,Lee, Josie H.,Teffera, Yohannes,Wang, Weiya,Youngblood, Beth D.,Yu, Violeta L.,Zhang, Maosheng,Gavva, Narender R.,Lehto, Sonya G.,Geuns-Meyer, Stephanie
, p. 2794 - 2809 (2016/04/10)
There has been significant interest in developing a transient receptor potential A1 (TRPA1) antagonist for the treatment of pain due to a wealth of data implicating its role in pain pathways. Despite this, identification of a potent small molecule tool possessing pharmacokinetic properties allowing for robust in vivo target coverage has been challenging. Here we describe the optimization of a potent, selective series of quinazolinone-based TRPA1 antagonists. High-throughput screening identified 4, which possessed promising potency and selectivity. A strategy focused on optimizing potency while increasing polarity in order to improve intrinisic clearance culminated with the discovery of purinone 27 (AM-0902), which is a potent, selective antagonist of TRPA1 with pharmacokinetic properties allowing for >30-fold coverage of the rat TRPA1 IC50 in vivo. Compound 27 demonstrated dose-dependent inhibition of AITC-induced flinching in rats, validating its utility as a tool for interrogating the role of TRPA1 in in vivo pain models.
An atom-economic approach to carboxylic acids via Pd-catalyzed direct addition of formic acid to olefins with acetic anhydride as a co-catalyst
Wang, Yang,Ren, Wenlong,Shi, Yian
supporting information, p. 8416 - 8419 (2015/08/06)
An effective Pd-catalyzed hydrocarboxylation of olefins using formic acid with acetic anhydride as a co-catalyst is described. A variety of carboxylic acids are obtained in good yields with high regioselectivities under mild reaction conditions without the use of toxic CO gas.
Facile palladium-catalyzed hydrocarboxylation of olefins without external CO gas
Wang, Yang,Ren, Wenlong,Li, Jingfu,Wang, Haining,Shi, Yian
supporting information, p. 5960 - 5963 (2015/02/19)
An effective Pd-catalyzed hydrocarboxylation of olefins with phenyl formate and formic acid is described. A variety of carboxylic acids are obtained in good yields with high regioselectivities under operationally simple conditions without the use of toxic CO gas.
The Synthesis of Phosphonobaclofen, an Antagonist of Baclofen
Chiefari, John,Galanopoulos, Speros,Janowski, Wit K.,Kerr, David I. B.,Prager, Rolf H.
, p. 1511 - 1518 (2007/10/02)
Phosphonobaclofen 3-amino-2-(4-chlorophenyl)propylphosphonic acid, has been synthesized in five steps from ethyl 3-(4-chlorophenyl)but-2-enoate, and is a specific antagonist of baclofen.The alternative synthetic pathways, involving conjugate addition of phosphite to 2-(4-chlorophenyl)propenenitrile and of cyanide to 2-(4-chlorophenyl)ethylphosphonate ester, failed.Cyanide ion did add efficiently to ethyl 3-(4-chlorophenyl)-2-diethoxyphosphinylprop-2-enoate and hydrogenation followed by hydrolysis of the product gave (2 S, 3 S)- and (2R, 3 R)-4-amino-3-(4-chlorophenyl)-2-phosphonobutanoic acid, which is also undergoing pharmacological evaluation.
