538-56-7Relevant academic research and scientific papers
UNE METHODE SIMPLE ET RAPIDE DE PREPARATION DES ANHYDRIDES D'ACIDES CARBOXYLIQUES A PARTIR DE LEURS CHLORURES D'ACIDES, AVEC CATALYSE PAR TRANSFERT DE PHASE
Roulleau, Fabienne,Plusquellec, Daniel,Brown, Eric
, p. 4195 - 4196 (1983)
Symmetrical anhydrides of carboxylic acids were readily obtained, and in high yields under phase transfer conditions, i.e. by reacting the appropriate acid chloride in toluene solution (containing 0.1 eq. of n-Bu4N+ Cl-), with 20percent aqueous sodium hydroxide solution.
Isothiourea-Catalyzed Enantioselective Synthesis of Tetrahydro-α-carbolinones
Liu, Honglei,Slawin, Alexandra M. Z.,Smith, Andrew D.
supporting information, p. 1301 - 1305 (2020/02/25)
An isothiourea-catalyzed enantioselective annulation protocol using indolin-2-imines with a series of α,β-unsaturated p-nitrophenyl esters for the synthesis of tetrahydro-α-carbolinones was developed. Using 5 mol % of the isothiourea HyperBTM as the Lewis base catalyst, this process allows the enantioselective preparation of a range of C(4)-substituted tetrahydro-α-carbolinones in good to excellent yield and with high enantioselectivity (20 examples, 32-99% yield and up to 99:1 er).
Photocatalytic Systems with Flavinium Salts: From Photolyase Models to Synthetic Tool for Cyclobutane Ring Opening
Hartman, Tomá?,Cibulka, Radek
supporting information, p. 3710 - 3713 (2016/08/16)
Two new photocatalytic systems based on flavinium species formed in situ by protonation of riboflavin-tetraacetate (1) with triflic acid or prepared in advance via alloxazine quaternization are presented as effective tools for oxidative cyclobutane ring [2 + 2] cycloreversion using visible light. The system with 1,3-dimethyl-8-trifluoromethylalloxazinium perchlorate (2c) was found to be superior allowing an acid-free mild procedure, which results in the opening of cyclobutanes with high oxidation potential (up to 2.14 V) and/or with sensitive groups (e.g., furan) without side reactions.
Acid anhydrides and the unexpected N,N-diethylamides derived from the reaction of carboxylic acids with Ph3P/I2/Et3N
Phakhodee, Wong,Duangkamol, Chuthamat,Wangngae, Sirilak,Pattarawarapan, Mookda
supporting information, p. 325 - 328 (2016/01/12)
The formation of acid anhydrides from the phosphorous-mediated activation of carboxylic acids was investigated. Under various systems, activation of benzoic acid in the presence of base led to the formation of benzoic anhydride at different rates depending on the reactivity of the reagents. Using the Ph3P-I2/Et3N combination, most aryl acids were converted into the corresponding anhydrides in high yields within 5-10 min. However, for nitro-substituted derivatives, unexpectedly, N,N-diethylamides were isolated without anhydride formation. These results indicated the pronounced effect of substituents in governing these potential side reactions which can significantly affect the yields of acylation reactions promoted by phosphonium species.
The use of BrCCl3-PPh3 in Appel type transformations to esters, O-acyloximes, amides, and acid anhydrides
Al-Azani, Mariam,al-Sulaibi, Mazen,al Soom, Nuha,Al Jasem, Yosef,Bugenhagen, Bernhard,Al Hindawi, Bassam,Thiemann, Thies
, p. 921 - 932 (2016/08/08)
Esters, acyloximes, amides and acid anhydrides have been prepared from the respective carboxylic acids, oximes, amines and alcohols by the use of the reagent combination BrCCl3-PPh3. The reactions obviate the handling acyl halides or more aggressive reagents PCl3, POCl3, or SOCl2. Furthermore, the environmentally hazardous CCl4 used in Appel-type reactions is replaced with BrCCl3, a reagent of less environmental concern.
Oxidative self-coupling of aldehydes in the presence of CuCl2/TBHP system: Direct access to symmetrical anhydrides
Saberi, Dariush,Shojaeyan, Fatemeh,Niknam, Khodabakhsh
supporting information, p. 566 - 569 (2016/01/20)
A simple synthesis of symmetrical anhydrides has been developed. Using tert-butylhydroperoxide (TBHP) as the oxidant and copper(II) chloride as the catalyst in acetonitrile, various aromatic and heteroaromatic aldehydes were reacted to provide symmetrical anhydrides in modest to good yields.
Functional group tolerance in organocatalytic regioselective acylation of carbohydrates
Ueda, Yoshihiro,Muramatsu, Wataru,Mishiro, Kenji,Furuta, Takumi,Kawabata, Takeo
supporting information; experimental part, p. 8802 - 8805 (2015/05/06)
(Chemical Equation Presented) Organocatalytic regioselective acylation of mono- and disaccaharides with various functionalized acid anhydrides has been developed. Acylation of octyl β-D-glucopyranoside with acid anhydrides derived from R-amino acids, cinnamic acid, and gallic acid took place at C(4)-OH with 67-94% regioselectivity in the presence of catalyst 1. Regioselective acylation of disaccharides with functionalized acid anhydrides was also achieved with 78-94% selectivity. Especially, a disaccharide with seven free hydroxy groups (X = OH, R′ = H) underwent acylation at C(4)-OH with 78% regioselectivity in the presence of 1. Thus, functional group tolerance in the regioselective acylation catalyzed by 1 was found to be high.
5H-3-oxa-Octafluoropentanesulfonyl fluoride: a novel and efficient condensing agent for esterification, amidation and anhydridization
Yan, Zhaohua,Tian, Weisheng,Zeng, Fanrong,Dai, Yanfeng
experimental part, p. 2727 - 2729 (2009/09/06)
The use of 5H-3-oxa-octafluoropentanesulfonyl fluoride (HCF2CF2OCF2CF2SO2F) as a novel and efficient condensing reagent for esterification of carboxylic acids with alcohols and amidation of carboxylic acids with amines in the presence of 1,3-diazabicyclo[5.4.0]-undec-7-ene (DBU) is reported. HCF2CF2OCF2CF2SO2F cannot serve as a condensing agent for anhydridization of carboxylic acids, however, HCF2CF2OCF2CF2SO2F/(CH3)3SiCN system can mediate anhydridization of some aromatic carboxylic acids.
Reaction of dicarbonates with carboxylic acids catalyzed by weak Lewis acids: General method for the synthesis of anhydrides and esters
Bartoli, Giuseppe,Bosco, Marcella,Carlone, Armando,Dalpozzo, Renato,Marcantoni, Enrico,Melchiorre, Paolo,Sambri, Letizia
, p. 3489 - 3496 (2008/09/19)
The reaction between carboxylic acids (RCOOH) and dialkyl dicarbonates [(R1OCO)2O], in the presence of a weak Lewis acid such as magnesium chloride and the corresponding alcohol (R1OH) as the solvent, leads to the esters RCOOR1 in excellent yields. The mechanism involves a double addition of the acid to the dicarbonate, affording a carboxylic anhydride [(RCO)2O], R1OH and carbon dioxide. The esters arise from the attack of the alcohols on the anhydrides. Exploiting the lesser reactivity of tert-butyl alcohol in comparison with other alcohols, a clean synthesis of both carboxylic anhydrides and esters has been set up. In the former reaction, an acid/Boc2O molecular ratio of 2:1 leads to the anhydride in good to excellent yields, depending on the stability of the resulting anhydride to the usual workup conditions. In the latter reaction, stoichiometric mixtures of the acid and Boc2O are allowed to react with a twofold excess of a primary alcohol, secondary alcohol or phenol (R 2OH) to give the corresponding esters (RCOOR2). Purification of the products is particularly easy since all byproducts are volatile or water soluble. A very easy chromatography is required only in the case of nonvolatile alcohols. A broad variety of sensitive functional groups is tolerated on both the acid and the alcohol, in particular a high chemoselectivity is observed. In fact, no transesterification processes occur with the acid-sensitive acetoxy group and methyl esters. Georg Thieme Verlag Stuttgart.
Synthesis of anhydrides from acyl chlorides under ultrasound condition
Hu, Yulai,Wang, Jin-Xian,Li, Shihua
, p. 243 - 248 (2007/10/03)
A convenient and general method for the synthesis of symmetrical anhydrides under ultrasound conditions is described.
