7780-16-7Relevant academic research and scientific papers
Direct C-C Bond Formation from Alkanes Using Ni-Photoredox Catalysis
Ackerman, Laura K. G.,Martinez Alvarado, Jesus I.,Doyle, Abigail G.
, p. 14059 - 14063 (2018/10/24)
A method for direct cross coupling between unactivated C(sp3)-H bonds and chloroformates has been accomplished via nickel and photoredox catalysis. A diverse range of feedstock chemicals, such as (a)cyclic alkanes and toluenes, along with late-stage intermediates, undergo intermolecular C-C bond formation to afford esters under mild conditions using only 3 equiv of the C-H partner. Site selectivity is predictable according to bond strength and polarity trends that are consistent with the intermediacy of a chlorine radical as the hydrogen atom-abstracting species.
Palladium-catalyzed aerobic oxidative coupling of acyl chlorides with arylboronic acids
Chen, Jiuxi,Peng, Yong,Liu, Miaochang,Ding, Jinchang,Su, Weike,Wu, Huayue
supporting information, p. 2117 - 2122 (2012/11/07)
The first example of a palladium-catalyzed aerobic oxidative coupling of acyl chlorides with arylboronic acids has been developed, leading to a wide range of aryl benzoates in good to excellent yields. This catalytic system shows broad functional group tolerance. Preliminary mechanistic experiments using deuterium labeling showed that the oxygen atom was derived from dioxygen. Copyright
Comparisons of O-acylation and Friedel-Crafts acylation of phenols and acyl chlorides and Fries rearrangement of phenyl esters in trifluoromethanesulfonic acid: Effective synthesis of optically active homotyrosines
Murashige, Ryo,Hayashi, Yuka,Ohmori, Syo,Torii, Ayuko,Aizu, Yoko,Muto, Yasuyuki,Murai, Yuta,Oda, Yuji,Hashimoto, Makoto
experimental part, p. 641 - 649 (2011/03/19)
Reactions involving phenol derivatives and acyl chlorides have to be controlled for competitive O-acylations and C-acylations (Friedel-Crafts acylations and Fries rearrangements) in acidic condition. The extent for these reactions in trifluoromethanesulfonic acid (TfOH), which is used as catalyst and solvent, is examined. Although diluted TfOH was needed for effective O-acylation, concentrated TfOH was required for effective C-acylations in mild condition. These results have been applied to the novel synthesis of homotyrosine derivatives. Both Fries rearrangement of N-TFA-Asp(OBn)-OMe and Friedel-Crafts acylation of phenol with N-TFA-Asp(Cl)-OMe in TfOH afforded the homotyrosine skeleton, followed by reduction and deprotection afforded homotyrosines maintaining stereochemistry of Asp as an optically pure form.
O-arylation of carboxylic acids using (phenyl)[2-(trimethylsilyl)phenyl] iodonium triflate as a precursor of arynes
Xue, Jian,Huang, Xian
, p. 2179 - 2185 (2008/02/05)
Using (phenyl)[2-(trimethylsilyl)phenyl]iodonium triflate as a precursor of arynes, Larock's method for O-arylation of carboxylic acids and arynes was developed. A variety of acids including simple aliphatic carboxylic acids, aromatic carboxylic acids, allenoic acids, and p-toluenesulfonic acid under mild reaction conditions could generate the aryl esters. Copyright Taylor & Francis Group, LLC.
An eco-friendly method for the synthesis of aryl and alkyl esters of carboxylic acids using acid activated Indian bentonite
Vijayakumar,Iyengar, Pushpa,Nagendrappa, Gopalpur,Prakash, B. S. Jai
, p. 922 - 925 (2007/10/03)
Esterification of various carboxylic acids with phenol and alcohols has been achieved using acid activated Indian bentonite (AAIB) as catalyst. The catalyst is versatile, and the reaction is found to work well for primary, secondary and tertiary alcohols. The yields are very good under specific reaction conditions.
Mapping the substrate selectivity and enantioselectivity of esterases from thermophiles
Somers, Neil A.,Kazlauskas, Romas J.
, p. 2991 - 3004 (2007/10/03)
To identify potential applications of nineteen esterases from thermophiles, we mapped their substrate selectivity and enantioselectivity using a library of 50 esters. We measured the selectivities colorimetrically using Quick E, which uses pH indicators to detect hydrolysis and a chromogenic reference compound as an internal control. The substrate selectivity mapping revealed one esterase, E018b, with a strong preference for acetyl esters (14- to 25-fold over hexanoate). The enantioselectivity mapping revealed a number of cases of high enantioselectivity. Thirteen of the 19 esterases showed moderate or better enantioselectivity (>19) toward 1-phenethyl butyrate favoring the (R)-enantiomer and two esterases (E008, E013) showed moderate or better enantioselectivity (>20) toward methyl 2-chloropropionate favoring the (S)-enantiomer. Three esterases (E001, E004, E005) showed high (>46) enantioselectivity toward menthyl acetate favoring the (R)-enantiomer. This rapid mapping of the selectivity simplifies the characterization of new enzymes.
Highly efficient esterification of carboxylic acids with alcohols by montmorillonite enwrapped titanium as a heterogeneous acid catalyst
Kawabata, Tomonori,Mizugaki, Tomoo,Ebitani, Kohki,Kaneda, Kiyotomi
, p. 9205 - 9208 (2007/10/03)
Montmorillonite-enwrapped titanium catalyst was found to efficiently promote the esterification of carboxylic acids with alcohols. In comparison to other catalysts reported to date, this heterogeneous catalyst offers a remarkably simple workup procedure, and is reusable without any appreciable loss in its activity and selectivity.
Regioselective Acylation of Anisole with Carboxylic Acids over HZSM-5 Catalyst
Wang, Q. L.,Ma, Yudao,Ji, Xingdong,Yan, Hao,Qiu, Qin
, p. 2307 - 2308 (2007/10/02)
Over a HZSM-5 catalyst, the liquid-phase acylation of anisole with carboxylic acid gave the phenyl carboxylic ester at lower temperatures (423 K) 4-acyl anisole was the predominant product.
Xanthone-2-carboxylic acid compounds
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, (2008/06/13)
Novel xanthone-2-carboxylic acid compounds of the formula STR1 wherein A is selected from the group consisting of --COOR', a 1H-tetrazol-5-yl and a 1H-tetrazolylcarbamoyl, R' is selected from the group consisting of hydrogen, alkyl of 1 to 5 carbon atoms and cation of a non-toxic, pharmaceutically acceptable organic or inorganic base, R is selected from the group consisting of hydrogen, alkyl of 1 to 9 carbon atoms, alkoxy of 1 to 9 carbon atoms and alkoxy alkoxy of 2 to 9 carbon atoms and X is selected from the group consisting of STR2 AND STR3 WHEREIN R1 is alkyl of 1 to 5 carbon atoms, R2 is selected from the group consisting of hydrogen, acyl of an aliphatic acid of 1 to 5 carbon atoms, aroyl of 7 to 8 carbon atoms, araliphatic acyl with 1 to 5 carbon atoms in the aliphatic portion and 6 or 7 carbon atoms in the aryl portion, aralkyl of 7 to 8 carbon atoms, arylsulfonyl, a carbamoyl, a carboxyalkyl of 1 to 5 carbon atoms, --CO--(CH2)n -- Het where n is 1, 2 or 3 and Het is a N-attached nitrogen heterocyclic which may contain an additional heteroatom and STR4 AND Alk is alkyl of 1 to 5 carbon atoms and R3 is arylsulfonyl which possess anti-allergic properties and their preparation.
