Here we describe the synthesis and application of a novel 2,3-dicyclohexylsuccinimide (Cy2SI) protecting group towards regioselective purine glycosylation and alkylation reactions. This bulky protecting group promotes high regioselectivity during the glycosylation (as well as diastereoselectivity) or alkylation of purines using Hoffer's chlorosugar or tert-butyl bromoacetate, respectively. Cy2S...

The effect of the ortho alkylation of perylene bisimides on the alignment and self-assembly properties has been studied. It was found that the dichroic properties of perylene bisimides in a liquid crystal host can be reversed with a single synthetic step by ortho alkylation. Furthermore, a solvent-induced growth of ultralong organic n-type semiconducting fibrils from non-ortho-alkylated perylen...

A new organocatalytic asymmetric domino Michael-alkylation reaction of methyleneindolinones and γ-halogenated-β-ketoesters is described. A variety of spiro-cyclopentanoneoxindoles were obtained in high yields (up to 96%), good diastereoselectivities (up to 12 : 1 dr) and excellent enantioselectivities (up to >99% ee) via α-alkylation. Interestingly, O-alkylated products with tetronic acid motif...

A novel approach for the allylic alkylation of anilines, hydrazides, indole derivatives and additional interesting nucleophiles is described, which involves direct use a variety alcohols under...

7-Hydroxy-quinine was synthesized by an asymmetric aldol reaction that establishes the C8 and C9 stereochemistry, followed by construction of the 3-vinyl-quinuclidine azabicyclo[2.2.2]octane by C3-C4 ring closure using an intramolecular palladium-mediated allylic alkylation with excellent regio- and diastereoselectivity. This is the first report of a ketone-enolate-stereocontrolled allylic alky...

An efficient synthetic approach to the core structure of the manzamine alkaloids is reported, particularly in relation to incorporating a one-carbon unit in ring B from which the aldehyde in ircinal A or the beta-carboline unit in manzamine A could potentially be generated. The key steps involve a Johnson-Claisen rearrangement, enolate alkylation, dithiane alkylation and a stereoselective intra...

A catalytic enantioselective synthesis of (+)-eucomic acid is reported. A palladium-catalyzed asymmetric allylic alkylation is employed to access the chiral tetrasubstituted α-hydroxyacid moiety found in the natural product. The protecting group strategy was investigated, and a protecting group manipulation was made without any appreciable deleterious effects in the allylic alkylation reaction....

The method of Kouklovsky and coworkers for the enantioselective alkylation of cyclic N-naphthoyl derivatives of amino acids was used to introduce a (13)C label into one of the two enantiotopic methyl groups of 2-aminoisobutyric acid (Aib) by retentive alkylation of L-alanine with (13)CH(3)I. Conditions were identified for optimization of yield and enantiomeric purity, and the absolute configura...