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
Functionalized Beta 1,6 Glucosamine Disaccharides and Process for Their Preparation
申请人:Moutel Stephane
公开号:US20100168054A1
公开(公告)日:2010-07-01
The present invention relates to a novel process for the chemical synthesis of β-(1->6)-linked glucosamine disaccharides of the formula (1) and (intermediate) compounds relating to the process. According to further aspects the invention relates to compositions comprising the compounds and the use of the compounds in the synthesis of disaccharides and medicine.
Revisiting Glycosylations Using Glycosyl Fluoride by BF<sub>3</sub>·Et<sub>2</sub>O: Activation of Disarmed Glycosyl Fluorides with High Catalytic Turnover
Catalytic glycosylations with glycosylfluorides using BF3·Et2O are presented. Glycosylations with both armed and disarmed donors were efficiently catalyzed by 1 mol% of BF3·Et2O in a nitrogen-filled glovebox without the use of dehydrating agents. Our finding is in sharp contrast with conventional BF3·Et2O-mediated glycosylations, where excess Lewis acid and additives are required. Mechanistic studies
Highly β-selective mannosylation of 4,6-O-benzylidene-mannopyranosyl-N-phenyltrifluoroacetimidate (α/β, 5:95, 93% yield) has been realized by utilizing a dual Lewis acid/cation trap catalyst, TMSB(C6F5)4. The obtained Manβ1-4GlcNTroc unit can be readily converted to a variety of N-linked oligosaccharides.