4484-35-9Relevant academic research and scientific papers
PdII-Catalyzed Site-selective β- and γ-C(sp3)-H Arylation of Primary Aldehydes Controlled by Transient Directing Groups
Li, Yi-Hao,Ouyang, Yuxin,Chekshin, Nikita,Yu, Jin-Quan
supporting information, p. 4727 - 4733 (2022/04/07)
Pd(II)-catalyzed site-selective β- and γ-C(sp3)-H arylation of primary aldehydes is developed by rational design of L,X-type transient directing groups (TDG). External 2-pyridone ligands are identified to be crucial for the observed reactivity. By minimizing the loading of acid additives, the ligand effect is enhanced to achieve high reactivities of the challenging primary aldehyde substrates. Site selectivity can be switched from the proximate to the relatively remote position by changing the bite angle of TDG to match the desired palladacycle size. Experimental and computational investigations support this rationale for designing TDG to potentially achieve remote site-selective C(sp3)-H functionalizations.
Ligand-controlled divergent dehydrogenative reactions of carboxylic acids via C–H activation
Wang, Zhen,Hu, Liang,Chekshin, Nikita,Zhuang, Zhe,Qian, Shaoqun,Qiao, Jennifer X.,Yu, Jin-Quan
, p. 1281 - 1285 (2021/12/10)
Dehydrogenative transformations of alkyl chains to alkenes through methylene carbon-hydrogen (C–H) activation remain a substantial challenge. We report two classes of pyridine-pyridone ligands that enable divergent dehydrogenation reactions through palladium-catalyzed b-methylene C–H activation of carboxylic acids, leading to the direct syntheses of a,b-unsaturated carboxylic acids or g-alkylidene butenolides. The directed nature of this pair of reactions allows chemoselective dehydrogenation of carboxylic acids in the presence of other enolizable functionalities such as ketones, providing chemoselectivity that is not possible by means of existing carbonyl desaturation protocols. Product inhibition is overcome through ligand-promoted preferential activation of C(sp3)–H bonds rather than C(sp2)–H bonds or a sequence of dehydrogenation and vinyl C–H alkynylation. The dehydrogenation reaction is compatible with molecular oxygen as the terminal oxidant.
Enantioselective Synthesis of N?H-Free 1,5-Benzothiazepines
Wang, Guojin,Tang, Yu,Zhang, Yu,Liu, Xiaohua,Lin, Lili,Feng, Xiaoming
supporting information, p. 554 - 557 (2017/01/18)
An enantioselective sulfa-Michael-cyclization reaction was developed for the synthesis of 1,5-benzothiazepines with versatile pharmacological activities. The reaction between 2-aminothiophenol and α,β-unsaturated pyrazoleamides gave direct access to N?H-free 1,5-benzothiazepines in the presence of a chiral N,N′-dioxide/Yb(OTf)3complex. Excellent enantioselectivities (up to 96 % ee) and high yields (up to 99 %) were obtained for a broad range of substrates under mild reaction conditions. This method provided a facile approach to the antidepressant drug (R)-(?)-Thiazesim.
Enantioselective Intermolecular Addition of Aliphatic Amines to Acyclic Dienes with a Pd-PHOX Catalyst
Adamson, Nathan J.,Hull, Ethan,Malcolmson, Steven J.
supporting information, p. 7180 - 7183 (2017/06/05)
We report a method for the catalytic, enantioselective intermolecular addition of aliphatic amines to acyclic 1,3-dienes. In most cases, reactions proceed efficiently at or below room temperature in the presence of 5 mol % of a Pd catalyst bearing a PHOX ligand, generating allylic amines in up to 97:3 er. The presence of an electron-deficient phosphine within the ligand not only leads to a more active catalyst but also is critical for achieving high site selectivity in the transformation.
Method for synthesizing alpha, beta-unsaturated acid by using formic acid and alkine
-
Paragraph 0024, (2016/10/27)
The invention relates to a method for synthesizing alpha, beta-unsaturated acid by using formic acid and alkine, in particular to a method for synthesizing alpha, beta-unsaturated acid by using formic acid and alkine under the effect of a nickel catalyst. The consumption of the catalyst is 0.01 to 2 mol percent of the quantity of a substrate substance; the consumption of estolide is 3 to 30 mol percent of the quantity of the substrate substance; the pressure of acetylene gas is 1 to 10 MPa; the reaction temperature is 25 to 100 DEG C; the reaction time is 5 to 12 hours. The method has the advantages that the existing alkine hydrocarboxylation defects are overcome; the use of toxic carbon monoxide gas does not needed; the reaction conditions of the whole process are mild; the efficiency is high; the selectivity is good; the method belongs to a method for preparing the alpha, beta-unsaturated acid with the advantages that the method conforms to green chemistry and has good application aspects; good industrial application prospects are realized.
Nickel-catalyzed hydrocarboxylation of alkynes with formic acid
Hou, Jing,Yuan, Ming-Lei,Xie, Jian-Hua,Zhou, Qi-Lin
supporting information, p. 2981 - 2984 (2016/06/06)
A protocol for nickel-catalyzed hydrocarboxylation of alkynes with formic acid was developed. The protocol allowed for highly efficient synthesis of acrylic acid with a TON of up to 7700.
Discovery of vinylcycloalkyl-substituted benzimidazole TRPM8 antagonists effective in the treatment of cold allodynia
Calvo, Raul R.,Meegalla, Sanath K.,Parks, Daniel J.,Parsons, William H.,Ballentine, Shelley K.,Lubin, Mary Lou,Schneider, Craig,Colburn, Raymond W.,Flores, Christopher M.,Player, Mark R.
scheme or table, p. 1903 - 1907 (2012/04/04)
Thermosensitive transient receptor potential melastatin 8 (TRPM8) antagonists are considered to be potential therapeutic agents for the treatment of cold hypersensitivity. The discovery of a new class of TRPM8 antagonists that shows in vivo efficacy in the rat chronic constriction injury (CCI)-induced model of neuropathic pain is described.
Discovery of 4-[4-({(3R)-1-butyl-3-[(R)-cyclohexyl(hydroxy)methyl]-2,5- dioxo-1,4,9-triazaspiro[5.5]undec-9-yl}methyl)phenoxy]benzoic acid hydrochloride: A highly potent orally available CCR5 selective antagonist
Nishizawa, Rena,Nishiyama, Toshihiko,Hisaichi, Katsuya,Minamoto, Chiaki,Murota, Masayuki,Takaoka, Yoshikazu,Nakai, Hisao,Tada, Hideaki,Sagawa, Kenji,Shibayama, Shiro,Fukushima, Daikichi,Maeda, Kenji,Mitsuya, Hiroaki
experimental part, p. 4028 - 4042 (2011/08/21)
Based on the original spirodiketopiperazine design framework, further optimization of an orally available CCR5 antagonist was undertaken. Structural hybridization of the hydroxylated analog 4 derived from one of the oxidative metabolites and the new orally available non-hydroxylated benzoic acid analog 5 resulted in another potent orally available CCR5 antagonist 6a as a clinical candidate. Full details of a structure-activity relationship (SAR) study and ADME properties are presented.
Spirodiketopiperazine-based CCR5 antagonist: Discovery of an antiretroviral drug candidate
Nishizawa, Rena,Nishiyama, Toshihiko,Hisaichi, Katsuya,Minamoto, Chiaki,Matsunaga, Naoki,Takaoka, Yoshikazu,Nakai, Hisao,Jenkinson, Stephen,Kazmierski, Wieslaw M.,Tada, Hideaki,Sagawa, Kenji,Shibayama, Shiro,Fukushima, Daikichi,Maeda, Kenji,Mitsuya, Hiroaki
scheme or table, p. 1141 - 1145 (2011/04/16)
Following the discovery that hydroxylated derivative 3 (Fig. 1) was one of the oxidative metabolites of the original lead 1, it was found that hydroxylated compound 4 possesses higher in vitro anti-HIV potency than the corresponding non-hydroxylated compo
HETEROCYCLIC DERIVATIVE HAVING INHIBITORY ACTIVITY ON TYPE-I 11 -HYDROXYSTEROID DEHYDROGENASE
-
Page/Page column 173-174, (2010/08/07)
Disclosed is a compound which is useful as an 11β-hydroxysteroid dehydrogenase type 1 inhibitor. A compound represented by the formula: its pharmaceutically acceptable salt, or a solvate thereof, wherein X is O or S, a broken line and a wavy line represent the presence or the absence of a bond, (i) when a broken line represents the presence of a bond, a wavy line represents the absence of a bond, R2 and R3 are each independently hydrogen, halogen, cyano, hydroxy, carboxy, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl or the like, (ii) when a broken line represents the absence of a bond, a wavy line represents the presence of a bond, R1 and R4 are each independently hydrogen, halogen or the like, R2 and R3 are each independently hydrogen, halogen, cyano, hydroxy, carboxy, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl or the like, and R5 and R6 are each independently hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl or the like.
