An efficient and selective method was developed for the deprotection of triethylsilyl (TES) ethers using formic acid in methanol (5-10%) or in methylene chloride 2-5%) with excellent yields. TES ethers are selectively deprotected to the corresponding alcohols in high yields using formic acid in methanol under mild reaction conditions. Other hydroxyl protecting groups like t-butyldimethylsilyl (...

This communication describes the chemoselective metal-free reduction of tertiary amides to the corresponding amines. Hantzsch ester is used as a mild reducing agent for the reduction of trifluoromethanesulfonic anhydride activated amides providing the tertiary amines with high functional group tolerance.

The direct redox reaction (galvanic displacement) between Pd(2+) and substrate Si was used to deposit Pd on Si, and the Pd-Si catalysts enabled a chemoselective hydrogenation of para-chloronitrobenzene with the selectivity for para-chloroaniline higher than 99.9% at complete conversion of para-chloronitrobenzene.

2,3-Unsaturated-4-keto glycosyl acetates were found to exhibit low reactivity under several glycosylation conditions. Chemoselective glycosylations were effectively performed using 2,3-unsaturated glycosyl and 2,3-dideoxy glycosyl acetates as armed glycosyl donors, and 2,3-unsaturated-4-keto glycosyl acetates as disarmed glycosyl donors.

A novel synthesis of the aggregation pheromone of the Colorado potato beetle, Leptinotarsa decemlineata, has been developed based on a Sharpless asymmetric epoxidation in combination with a chemoselective alcohol oxidation using catalytic [(neocuproine)PdOAc]2OTf2. Employing this approach, the pheromone was synthesized in 3 steps, 80% yield and 86% ee from geraniol.

[reaction: see text] 1,1,3,3-Tetramethylguanidine (TMG)(1), a nitrogen organic base, is a convenient and useful reagent for chemoselective deprotection of both silyl and acetyl groups on acidic hydroxyl groups such as phenol and carboxylic acid without affecting aliphatic silyl and acetyl groups. The chemoselectivity is dependent on the acidity of the hydroxyl group.

Chemoselective phosphine-catalyzed cascade [2 + 2 + 2] and [2 + 2 + 1] annulations between two molecules of 2-arylmethylidene cyanoacetates or malononitriles and one molecule of α,β-unsaturated ketones have been developed. Under the nucleophilic catalysis of PPh(3) or PBu(3) (10 mol%), a highly diastereoselective synthesis of polysubstituted cyclohexanes or cyclopentenes has been successfully a...

Hierarchically porous zeolite supported metal nanoparticles are successfully prepared through a base-assisted chemoselective interaction between the silicon species on the zeolite crystal surface and metal salts, in which in situ construction of mesopores and high dispersion of metal species are realized simultaneously.

Control of boronic acid speciation is presented as a strategy to achieve nucleophile chemoselectivity in the Suzuki-Miyaura reaction. Combined with simultaneous control of oxidative addition and transmetalation, this enables chemoselective formation of two C-C bonds in a single operation, providing a method for the rapid preparation of highly functionalized carbogenic frameworks.