Organocatalytic Asymmetric Atroposelective Construction of Axially Chiral 1,4-Distyrene 2,3-Naphthalene Diols
An efficient organocatalytic construction of enantioenriched axially chiral 1,4-distyrene 2,3-naphthalene diols through the nucleophilic addition of α-amido sulfone to in situ generated vinylidene o-quinone methide is described. The reaction pathway was investigated by isolating reaction intermediates and performing a kinetic resolution process. Axially chiral 1,4-distyrene 2,3-naphthalene diol was used as the chiral ligand for the enantioselective addition of diethylzinc to naphthalene formaldehyde. The preliminary results revealed that these adducts could be potentially used as ligands in asymmetric synthesis.
The first vinyl acetate mediated organocatalytic transesterification of phenols: A step towards sustainability
The present report outlines our efforts toward a simple yet elegant protocol for O-acylation of a wide variety of phenols. This highly enabling and solventless method relies on vinyl acetate as an innocuous acyl donor and DABCO as an organocatalyst. Operational simplicity, excellent yields, higher and faster conversion rates without excess reagents, a simple workup and essentially no need of columns are some of the salient features of the reported protocol.
Kumar, Manoj,Bagchi, Sourav,Sharma, Anuj
supporting information
p. 8329 - 8336
(2015/11/10)
A novel "pro-sensitizer" based sensing of enzymes using Tb(iii) luminescence in a hydrogel matrix
Chemically synthesized "pro-sensitizers" release the sensitizer in the presence of lipase or β-glucosidase, triggering a significant luminescence response from a lanthanide based hydrogel. The Royal Society of Chemistry 2012.
Bhowmik, Sandip,Maitra, Uday
supporting information; experimental part
p. 4624 - 4626
(2012/06/05)
Synthesis of catechols from phenols via Pd-catalyzed silanol-directed C-H oxygenation
A silanol-directed, Pd-catalyzed C-H oxygenation of phenols into catechols is presented. This method is highly site selective and general, as it allows for oxygenation of not only electron-neutral but also electron-poor phenols. This method operates via a silanol-directed acetoxylation, followed by a subsequent acid-catalyzed cyclization reaction into a cyclic silicon-protected catechol. A routine desilylation of the silacyle with TBAF uncovers the catechol product.
Huang, Chunhui,Ghavtadze, Nugzar,Chattopadhyay, Buddhadeb,Gevorgyan, Vladimir
p. 17630 - 17633
(2011/12/16)
Regioselective hydrolysis of diacetoxynaphthalenes catalyzed by Pseudomonas sp. lipase in an organic solvent
Depending on the relative positions of the acetyl groups in the aromatic rings, the Pseudomonas sp. lipase-catalyzed hydrolysis of diacetoxynaphthalenes in tert-butylmethyl ether proceeds regioselectively to afford the corresponding monoacetates.