A series of novel chiral Lewis base catalysts were synthesized from L-serine and applied in the hydrosilylation of β-enamino esters, in which the optimal one promoted the reactions to afford a wide variety of β-amino esters in good yields with good enantioselectivities. It is noteworthy that several cyclic substrates were hydrosilylated under the optimal conditions to give the cyclic β-amino es...

Epoxidizedmethyl esters were prepared by the transesterification of epoxidized soybean oil (ESBO). The transesterification was complete in 10min at 50 ◦C without loss of the epoxide function. Epoxidized methyl esters represent a renewable substrate that is readily converted into surfactants, fuel additives, and other industrial products. The implementation of this reaction will increase the ava...

1. The gas-liquid-chromatographic separations of the acetate, propionate, n-butyrate, isobutyrate and n-valerate esters of androsterone, aetiocholanolone and dehydroepiandrosterone were studied on a 1% neopentyl glycol sebacate column. The n-butyrate, isobutyrate and n-valerate esters were well resolved. 2. The three steroids derived from hydrolysed urinary 17-oxo steroid conjugate extracts wer...

A nickel-catalyzed α-arylation of esters and amides with phenol derivatives has been accomplished. In the presence of our unique nickel catalyst, prepared in situ from Ni(cod)2, 3,4-bis(dicyclohexylphosphino)thiophene (dcypt), and K3PO4, various esters and amides undergo α-arylation with O-arylpivalates or O-arylcarbamates to afford the corresponding coupling products. The thus obtained α-aryl ...

• draw the mechanism of ester hydrolysis under acidic and basic reaction conditions; • account for the irreversibility of the hydrolysis reaction under basic conditions; • form new esters by baseor acid-catalysed transesterification mechanisms; • draw the mechanism for cleaving tert-butyl esters and understand why the mechanism is different from that for methyl esters; • understand why protonat...

The copper-catalyzed diboration of ketones followed by an acid-catalyzed elimination leads to the formation of 1,1-disubstituted and trisubstituted vinyl boronate esters with moderate to good yields and selectivity. Addition of tosic acid to the crude diboration products provides the corresponding vinyl boronate esters upon elimination. The trisubstituted vinyl boronate esters are formed as the...

Control of boronic acid solution speciation is presented as a new strategy for the chemoselective synthesis of boronic esters. Manipulation of the solution equilibria within a cross-coupling milieu enables the formal homologation of aryl and alkenyl boronic acid pinacol esters. The generation of a new, reactive boronic ester in the presence of an active palladium catalyst also facilitates strea...

Carbene-catalyzed reaction of carboxylic esters has the potential to offer effective synthetic solutions that cannot be readily achieved by using the more conventional aldehyde-type substrates. Here we report the first carbene-catalyzed dynamic kinetic resolution of α,α-disubstituted carboxylic esters with up to 99:1 er and 99% yield. The present study clearly illustrates the unique power of ca...

In an attempt to minimize the gastric ulcerogenicity of 6-methoxyindan-1-acetic acid and 5,6-dimethoxyindan-1-acetic acid exhibiting high anti-inflammatory activity, we synthesized their esters, amides and nitrile derivatives. It was found that the anti-inflammatory activity of ethyl esters were almost equal to those of parent acids and phenylbutazone while other derivatives were less potent. T...

An efficient catalytic synthesis of α-amino-β-keto esters has been newly developed. Cross-coupling of various aldehydes with α-imino ester, catalyzed by N-heterocyclic carbene, leads chemoselectively to α-amino-β-keto esters in moderate to good yields with high atom efficiency. The reaction mechanism is discussed, and it is proposed that the α-amino-β-keto esters are formed under thermodynamic ...