Enantioenriched, diastereomerically pure (2-carbamoyloxy-1-alkenyl)cyclopropanes 22 are easily prepared via deprotonation of different allyl carbamates with n-butyllithium and (−)-sparteine (4). The mechanism of the cyclization reaction was determined and several substituted (S)-configured vinyl...
Dispersive liquid–liquid microextraction was used to preconcentrate three spirocyclic tetronic/tetramic acid derivatives (spirotetramat, spiromesifen and spirodiclofen) and five neonicotinoid (thiamethoxam, chlotianidin, imidacloprid, acetamiprid and thiacloprid) insecticides previously extract...
Fatty acid binding proteins (FABPs) serve as critical modulators of endocannabinoid signaling by facilitating the intracellular transport of anandamide and whose inhibition potentiates anandamide signaling. Our previous work has identified a novel small-molecule FABP inhibitor, α-truxillic acid...
Free fatty acid-2 (FFA2) receptor is a G-protein coupled receptor of interest in the development of therapeutics in metabolic and inflammatory disease areas. The discovery and optimization of an N-thiazolylamide carboxylic acid FFA2 agonist scaffold is described. Dual key objectives were to i) e...
Biopolymeric clay hydrogels composites, synthesized from crosslinking of carboxymethyl cellulose with citric acid in the presence of bentonite, were used to develop base triggered release formulations (TRFs) of thiamethoxam (3-(2-chloro-1,3-thiazol-5-ylmethyl)-5-methyl-1,3,5-oxadiazinan-4-yliden...
5-Benzylbarbituric acid derivatives were synthesized as a series of new, specific, and potent inhibitors of uridine phosphorylase. Among these, 5-(m-benzyloxy)benzyl-1-[(2-hydroxyethoxy)methyl] barbituric acid (5-benzyloxybenzylbarbituric acid acyclonucleoside, BBBA) was found to be the most pot...
Various pyrimidine acyclonucleosides (l-(2'-hydroxyethoxymethyl)uracils) are specific inhibitors of uridine phosphorylase [Niedzwicki et al., Biochem. Pharmac.30, 2097 (1981)]. 5-Benzyluracils have also been shown to inhibit this enzyme [Baker and Kelley. J. med. Chem.13, 461 (1970); Woodma...
A catalyst-free reaction of 1-(N-acylamino)alkyltriphenylphosphonium tetrafluoroborates with silyl enolates was developed to prepare β-amino carbonyl compounds. The reported method is a useful approach for the preparation of N-protected β-amino esters as well as N-protected β-amino ketones. T...
A catalytic, enantioselective Michael addition of β-keto esters to α,β-unsaturated carbonyl compounds was achieved by using a chiral biquinoline N,N′-dioxide–scandium trifluoromethanesulfonate complex as a catalyst. The corresponding Michael adducts were obtained in high yields and with ena...
Scandium trifluoromethanesulfonate is a useful Lewis acid catalyst for cleavage of acetates containing coordinative groups adjacent to the acetyl carbonyl. The reaction proceeds under weak acidic conditions at room temperature. Racemizable α-keto acyloxy compounds are deacetylated without racem...
Scandium trifluoromethanesulfonate in CD3OD is a very active catalyst for hydrogen/deuterium exchange at the aromatic nucleus of 1,3,5-trimethoxybenzene. The very low proticity of the system, spectrophotometric evidence, and easy iodination of the substrate point to the formation of a transient ...
Claisen-Schmidt condensation of 2,3,4,9-tetrahydro-1H-carbazol-1-one with 3-bromo-4-methoxy benzaldehyde afforded the 2-(3'-bromo-4'-methoxybenzylidene)-2,3,4,9-tetrahydro-1H-carbazol-1-one 3. Compound 3 was allowed to react with different organic reactants, hydroxylamine hydrochloride...
As an extension of our analysis of the effect of halogenation on thiourea TRPV1 agonists, we have now modified selected 4-hydroxy(or 4-amino)-3-methoxyphenyl acetamide TRPV1 agonists by 5- or 6-halogenation on the aromatic A-region and evaluated them for potency for TRPV1 binding and regulation ...
It was found that 3-amino-substituted 5-aminopyrazoles could be effectively prepared via hydrolytic decarboxylation of the corresponding 3,5-diaminopyrazole-4-carboxylates under microwave irradiation. The reactions required short time (4 min) and were successfully reproduced in a larger scale an...
A series of isobutyl 6-amino-4-aryl-5-cyano-2-methyl-4H-pyran-3-carboxylates (1–9) have been synthesized by the multicomponent reaction (MCR) between isobutyl ethylacetoacetate, aryl aldehydes and malononitrile using BF3:OEt2 as catalyst. The derived compounds have been analyzed by IR and NMR (...
We describe a one-pot four component synthesis of pyranopyroles from aryl aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate in the presence of catalytic amounts of an organocatalyst imidazole in water as medium. A plausible mechanism for the formation of imidazole catalyzed pyra...
Polyphenols, such as (+)-catechin and pyrogallol could be used to enhance stereochemical control in the lipase-catalyzed hydrolysis of alkynol benzoate esters, leading to increased enantioselectivities in the kinetic resolution of alkynols with lipase Amano AH.
Reaction of O-propargyl salicylaldehyde and related compounds with dialkylamines in the presence of copper(I) iodide gave 4-(alkylamino)-3-methylenechroman derivatives in good yields through the loss of one alkyl group of the dialkylamine. The reaction also worked well by employing 2-amino benza...
While the first total synthesis of modiolide A (1a), a 10-membered ring lactone with a marine-origin was achieved, an important chiral building block for constructing the chirality at C-4 in 1a, (S)-6-[(4-methoxybenzyl)oxy]-1-trimethylsilyl-1-hexyn-3-ol (3a) was obtained in as high as 96.1% ee. ...
Propargyl functionalised β-silylalkenals were easily prepared starting from suitable propargyl compounds by a silylformylation process. In particular the use of propargyl tosyl amides allowed the synthesis of α,β-unsaturated aldehydes through a two-step sequence of silylformylation–desilylat...
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