3195-37-7Relevant articles and documents
Direct C-C Bond Formation from Alkanes Using Ni-Photoredox Catalysis
Ackerman, Laura K. G.,Martinez Alvarado, Jesus I.,Doyle, Abigail G.
supporting information, 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.
Base catalyzed sustainable synthesis of phenyl esters from carboxylic acids using diphenyl carbonate
Kreye, Oliver,Meier, Michael A. R.
, p. 53155 - 53160 (2015/06/25)
Phenyl esters were obtained in moderate to high yields by reaction of aliphatic and aromatic carboxylic acids with one equivalent of diphenyl carbonate in the presence of catalytic amounts of tertiary amine bases, such as DBU, TBD and DMAP under neat conditions at elevated temperatures (>100°C).
O-acylation of substituted phenols with various alkanoyl chlorides under phase-transfer catalyst conditions
Simion, Alina Marieta,Hashimoto, Iwao,Mitoma, Yoshiharu,Egashira, Naoyoshi,Simion, Cristian
experimental part, p. 921 - 931 (2012/02/01)
Esterification of several types of mono-and disubstituted phenols with various mono-and dialkanoyl chlorides was performed in phase-transfer catalysis conditions, using tetrabutylammonium chloride in a mixture of aqueous NaOH and dichloromethane. The process is particularly efficient (almost quantitative yields) as well as rapid (only 5 min reaction time, at a temperature of0°C). Taylor & Francis Group, LLC.
Pyrrolizidine Alkaloid Analogues. Synthesis of Macrocyclic Diesters of (+/-)-Synthanecine A Containing 12- to 16-Membered Rings
Barbour, Robert H.,Robins, David J.
, p. 1923 - 1928 (2007/10/02)
The first macrocyclic diesters of 2,3-bis(hydroxymethyl)-1-methyl-2,5-dihydropyrrole (2) with ring sizes of 12 to 16 have been prepared.Esterification of the imidazolide (6) of phenyl hydrogen adipate with (+/-)-synthanecine A was achieved at the 6-position.Treatment of the phenyl ester (7) with 1-(trimethylsilyl)imidazole and a catalytic quantity of sodium phenoxide produced the corresponding imidazolide and resulted in silylation of the free hydroxy group to afford the synthanecine A derivative (8).Attempted desilylation of the activated ester (8) followed by lactonisation failed and mixtures of oligomers were probably formed.In the successful route, treatment of (+/-)-synthanecine A (2) with thionyl chloride afforded (+/-)-3-chloromethyl-2-hydroxymethyl-1-methyl-2,5-dihydropyrrolium chloride (3).Nucleophilic displacement of the allylic chloride was carried out with adipic (9a), pimelic (9b), suberic (9c), azelaic (9d), and sebacic (9e) acids in the presence of 1,8-diazabicycloundec-7-ene to yield the 7-monoesters (10a-e) of synthanecine A.Lactonisation of these monoesters was achieved via the pyridine-2-thiol esters to give the new macrocyclic diesters (4c-g) with ring sizes of 12 to 16 in low overall yield (12-16percent).Improved yields (25-30percent) of the dilactones (4c-g) were obtained after rigorous purification and crystallisation of the allylic chloride hydrochloride (3).
