Synthesis, Characterization, and Reaction of Crystalline Fischer’s Glucopyranosyl Isocyanate

Abstract

We have established a simple method for the preparation of crystalline Fischer's glucopyranosyl isocyanate 1. NMR spectroscopic analysis of 1 allowed the unambiguous determination of the stereochemistry at the anomeric position. Synthetic applications of glucopyranosyl isocyanate 1 were ex-

A Family of Hydrogels Based on Ureido‐Linked Aminopolyol‐Derived Amphiphiles and Bolaamphiphiles: Synthesis, Gelation under Thermal and Sonochemical Stimuli, and Mesomorphic Characterization

“…In addition, the range of isocyanates was expanded to 2,3,4,5,6-penta-O-acetyl-1-deoxy-1-isocyanato-d-glucitol (10), a valuable chiral precursor that can be employed in the construction of O-protected derivatives and bolaform ureas (see below). Compound 10 has recently been prepared in our laboratories from penta-O-acetylated d-glucamine hydrobromide by using both COCl 2 in toluene solution and triphosgene [3,16] Figure 1. Schematic and simplified representation of amphiphiles and bolaamphiphiles that combine protected and unprotected carbohydrate and long-chain hydrocarbons through a ureido spacer.…”

“…The reactions of aminopolyols 1-3 with isocyanates 4-6 gave rise to a series of asymmetrically substituted monoureas (11)(12)(13)(14)(15)(16)(17)(18)(19) with different structural variations of the headand tail-group moieties (Scheme 1).…”

5′-Uridyl derivatives of N-glycosyl allophanic acid and biuret

“…Urea 13 (100 mg, 0.306 mmol) was dissolved in dry toluene 290 (6 mL), then some freshly heated molecular sieves and crystalline isocyanate 17 21 (252 mg, 0.675 mmol) were added. The reaction mixture was stirred at reflux temperature until the reaction was complete ($1 day, TLC, 10:1 EtOAc/hexane).…”

“…20 In our experiments no discrete product could be isolated under catalytic hydrogenation over Pd-C, and in Ph 3 P or (CH 3 ) 3 Pmediated reductions. Therefore, we have investigated another possibility to produce the desired biuret by reaction of 5 0 -uridyl urea 13 and crystalline glucosyl isocyanate 21 17. Urea 13 was prepared from 4 by applying Staudinger-type conditions 22 (PPh 3 , NH 3 , CO 2 ).…”

Self‐Assembly of a Supramolecular, Three‐Dimensional, Spoked, Bicycle‐like Wheel

“…This 2D wheel structure is more rigid than macrocyclic hexagons because of its fixed spacefilling centerpiece, which also serves as a template for the outer ligands. Subsequent treatment with 2,3,4,6-tetra-O-acetyl-bd-glucopyranosyl isocyanate [15] afforded (66 %) the desired tris-tpy ligand R3, which was fully characterized by NMR spectroscopy and MS. Its 1 H NMR spectrum exhibited signals for two sets of protons in the aromatic region with an integration ratio of 2:1 for the tpy units, as well as one set of signals corresponding to protons of the alkyl linker and glucose. [12] To further functionalize the well-established tpy-based spoked-wheel assembly, the backbone and connectivity components of its original structure were redesigned.…”