Recognition properties of receptors consisting of imidazole and indole recognition units towards carbohydrates

• Monika Mazik and
• André Hartmann

Beilstein J. Org. Chem. 2010, 6, No. 9, doi:10.3762/bjoc.6.9

• units as the entities used in nature, and 2-aminopyridine group as a heterocyclic analogue of the asparagine/glutamine primary amide side chain, were prepared and their binding properties towards carbohydrates were studied. The design of these receptors was inspired by the binding motifs observed in the

• heterocyclic analogues of the asparagine/glutamine primary amide side chains (in analogy to the binding motif shown in Figure 1a) [31]. The compounds 1 and 2 were established as highly effective receptors for mono- and disaccharides and shown to display remarkable β- vs. α-anomer selectivity in the recognition

2-Phenyl- tetrahydropyrimidine- 4(1H)-ones – cyclic benzaldehyde aminals as precursors for functionalised β²-amino acids

• Markus Nahrwold,
• Arvydas Stončius,
• Anna Penner,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2009, 5, No. 43, doi:10.3762/bjoc.5.43

• . In the course of this study, an L-asparagine derivative was condensed with benzaldehyde and subsequently converted to orthogonally protected (R)-β2-homoaspartate. Keywords: β2-amino acids; cyclocondensation; diastereoselective alkylation; N,N-acetals; peptidomimetics; ring opening; self-regeneration

• centres (SRS) proposed by Seebach [29], condensation of L-asparagine and pivalaldehyde yields N,N′-acetal 1, which is converted to 2 by subsequent oxidative decarboxylation [25][28][30][31][32][33], hydrogenation of the resulting olefinic double bond [25][26][27][31][34][35], and final N,N′-protection

• tetrahydropyrimidine-4(1H)-ones. In contrast to literature known 2-alkyl-tetrahydropyrimidine-4(1H)-ones, the N1- and N3-carbamate functionalised compound 5 is selectively cleavable under mild conditions and can thus be considered as a versatile precursor for functionalised β2-amino acids. Starting from L-asparagine

Acid- mediated reactions under microfluidic conditions: A new strategy for practical synthesis of biofunctional natural products

• Katsunori Tanaka and
• Koichi Fukase

Beilstein J. Org. Chem. 2009, 5, No. 40, doi:10.3762/bjoc.5.40

• conditions enabled the preparation of key synthetic intermediates for oligosaccharides on a multi-gram scale, eventually leading to a total synthesis of the asparagine-linked oligosaccharide (N-glycan) [32]. A significant improvement has also been achieved for dehydration, which resulted in the industrial

• industrial synthesis of the bioactive natural products. Review 1. Application of microfluidic systems to the synthesis of asparagine-linked oligosaccharides Among the various types of oligosaccharide structures, asparagine-linked oligosaccharides (N-glycans) are prominent in terms of diversity and complexity

• prominent biological activity in a “practical” and a “industrial” manner. Synthetic strategy for asparagine-linked oligosaccharide on solid support and application of microfluidic systems to fragment synthesis. β-Mannosylation using an integrated microfluidic/batch system. Yield and β/α-ratio are analyzed