Renaissance of Traditional Organic Reactions under Microfluidic Conditions: A New Paradigm for Natural Products Synthesis
作者:Katsunori Tanaka、Koichi Fukase
DOI:10.1021/op900084f
日期:2009.9.18
synthesis for bioactive naturalproducts is described. Efficient procedures using the microfluidic system were developed for the large-scale synthesis of important synthetic units of asparagine-linked oligosaccharide in glycoprotein. Advantageous aspects of microfluidic conditions, i.e., efficient mixing, fast heat transfer, and residence time control led to cation-mediated reactions, such as α-sialylation
Synthesis of a Sialic Acid Containing Complex-Type<i>N</i>-Glycan on a Solid Support
作者:Katsunori Tanaka、Yohei Fujii、Hiroomi Tokimoto、Yasutaka Mori、Shin-ichi Tanaka、Guang-ming Bao、Eric R. O. Siwu、Aiko Nakayabu、Koichi Fukase
DOI:10.1002/asia.200800411
日期:2009.4.6
solid‐phase synthesis of N‐linked glycans featuring 1) highly stereoselective β‐mannosylation and microfluidic α‐sialylation and 2) efficient glycosylation of the N‐phenyltrifluoroacetimidate units on JandaJel resin is reported. Reagent concentration effects by a fluorous solvent are effectively applied, and the use of these methods results in the first synthesis of a sialic acid containing complex‐type N‐glycan
Synthesis and clusterization of Gal beta(1 -> 3)[NeuAc alpha(2 -> 6)]GlcNAc beta(1 -> 2)Man motif of the N-glycan, as the molecular probes for their biological evaluation, are reported. Key step is the quantitative and the completely alpha-selective sialylation of the C5-azide N-phenyltrifluoroacetimidate with the disaccharide acceptor, Gal beta(1 -> 3) GlcNTroc. Clusterization of the 16 molecules of trisaccharide motif was also achieved by the 'self-activating click reaction'. These probes could efficiently be labeled by biotin and/or other fluorescenceor radioactive reporter groups through either cross metathesis, acylation, Cu(I)-mediated Huisgen [2+3]-cycloaddition, or the azaelectrocyclization to utilize the various biological techniques. (C) 2010 Elsevier Ltd. All rights reserved.