[reaction: see text]. Cyclic amines may be prepared via a sequence of deprotection followed by intramolecular reductive amination of t-Boc-protected amino ketones under asymmetric transfer hydrogenation conditions. In cases where the corresponding imine reaction proceeds with high enantioselectivity, this is reflected in the one-step process.

The use of omonasteine (Omo) in sequential peptide ligation strategies extends the scope of homocysteine (Hcy) ligation to longer, methionine-rich proteins. Hcy-to-Omo conversion can be performed on-resin, while the Omo-to-Hcy deprotection can be performed in situ after peptide ligation. This strategy was successfully applied in the synthesis of the BRD7 bromodomain.

A concise total synthesis of PDE-II featuring copper-mediated double aryl amination with the combination of CuI, CsOAc, and Cs2CO3 is described. The highly substituted pyrroloindole skeleton was constructed by a one-pot five-step sequence including double aryl amination, beta-elimination, deprotection of a Cbz group, and removal of an Ns group followed by rearomatization.

Two isomeric N-(methoxycarbonylthienylmethyl)thioureas were synthesised by a sequence of radical bromination of methylthiophenecarboxylic esters, substitution with trifluoroacetamide anion, deprotection, formation of the corresponding isothiocyanates and addition of ammonia. The interaction of these new thiophene-based thioureas with inducible and neuronal nitric oxide synthase was evaluated. T...

An efficient and chemoselective cleavage of silyl ethers (primary, secondary and aromatic) by using catalytic quantities of trimethylsilyl bromide (TMSBr) in methanol is reported. A wide range of alkyl silyl ethers such as TBS, TIPS, and TBDPS can be chemoselectively cleaved in high yield in the presence of aryl silyl ethers. The deprotection of silyl esters was also achieved employing catalyti...

Alkylation of γ-cyclodextrin with 3 equiv. of 1,3-bis[bis(4-tert-butylphenyl)chloromethyl]benzene, followed by permethylation afforded selectively a singly capped (A,B), as well as two doubly capped (A,B:D,E and A,B:E,F) methylated γ-CDs. Deprotection with HBF4 gave quantitatively the corresponding diols and tetrols, which constitute valuable starting compounds for further functionalisation.

An efficient approach for the facile synthesis of a potent vaccine adjuvant RC-529 is described. The synthetic strategy relies on flexible use orthogonal protecting groups, which makes it possible to accomplish selective phosphorylation, glycosylation and acylation, respectively. In addition, readily cleaved 2-naphthylmethyl (Nap) ether allyl esters as permanent groups greatly facilitates final...

Short proteoglycan fragments are of great importance for biochemical research. The solid-phase synthesis such glycopeptides relies on excessive use glycosylated amino acids, extended reaction times, and additional post-assembly deprotection protocols. We employed high-shear mixing expedient equimolar O-glycopeptide assembly. further developed a stirring-based the solid support, thus completing ...

4,4'-Dimethoxytrityl, (DMTr), is at present commonly used for the protection of the 5'-terminal hydroxy function in solid phase DNA or RNA synthesis. During the oligonucleotide synthesis the first step, prior to coupling with the appropriately protected phosphoroamidite monomer, is the removal of the 5'-protecting group, (DMTr, detritylation) by a suitable protic acid. Strong protic acids, such...