Aldehyde Functionality (aldehyde + functionality)

Distribution by Scientific Domains

Selected Abstracts

1-Bis(methoxy)-4-bis(methylthio)-3-buten-2-one: Useful Three Carbon Synthon for Synthesis of Five and Six Membered Heterocycles with Masked (or Unmasked) Aldehyde Functionality.

CHEMINFORM, Issue 32 2003
Pranab K. Mahata
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Synthesis and characterization of injectable bioadhesive hydrogels for nucleus pulposus replacement and repair of the damaged intervertebral disc

J. Vernengo
Abstract Bioadhesive polymers are natural or synthetic materials that can be used for soft tissue repair. The aim of this investigation was to develop an injectable, bioadhesive hydrogel with the potential to serve as a synthetic replacement for the nucleus pulposus of the intervertebral disc or as an annulus closure material. Branched copolymers of poly(N -isopropylacrylamide) (PNIPAAm) and poly(ethylene glycol) (PEG) were blended with poly(ethylene imine) (PEI). This three component injectable system can form a precipitated gel at physiological temperature due to the phase transition of PNIPAAm. The injection of glutaraldehyde into the gel core will adhere the implant to the surrounding tissues. 1H NMR results indicated the successful physical incorporation of PEI into the PNIPAAm-PEG network by blending. In addition, the covalent crosslinking between the amine functionalities on the PEI and the aldehyde functionalities on the glutaraldehyde was verified using FTIR difference spectroscopy. Mechanical characterization of these blends showed a significant increase (p < 0.05) in compressive modulus following glutaraldehyde injection. The in vitro bioadhesive force studies with porcine skin showed a significant increase (p < 0.05) in the mean maximum force of detachment for PNIPAAm-PEG/PEI gels when glutaraldehyde was injected into the gel core. The results of this study indicate that the reactivity between amines and aldehyde functionalities can be exploited to impart bioadhesive properties to PNIPAAm-PEG/PEI copolymers. 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010 [source]

From Metacyclophanes to Cyclacenes: Synthesis and Properties of [6.8]3Cyclacene

Birgit Esser Dr.
Abstract Conjugated belts: [6.8]3cyclacene as the first hydrocarbon cyclacene was synthesized in a de novo strategy. Various [23]metacyclophanes are described as intermediates. The synthetic approach was extended to larger cyclacenes, and [24]metacyclophanes as precursors of [6.8]4cyclacene were synthesized. In this article we show synthetic pathways to [6.8]ncyclacenes demonstrated by the de novo synthesis of [6.8]3cyclacene as the first purely hydrocarbon cyclacene and of precursors for [6.8]4cyclacene. The design of the de novo synthesis by exploring alternative pathways is discussed and various precursors are shown. Crucial to the synthesis of [6.8]3cyclacene were two cyclization steps. The first is a Wittig trimerization reaction which yielded the hexamethyl substituted all - cis -[23]metacyclophanetriene. For the second cyclization step the methyl groups were converted to aldehyde functionalities by two subsequent oxidation steps of N-bromosuccinimide (NBS) bromination and oxidation with 2-iodoxybenzoic acid (IBX). The final cyclization of the second set of double bonds was achieved by a McMurry-coupling reaction. Towards the synthesis of [6.8]4cyclacene different synthetic pathways to methyl substituted all - cis -[24]metacyclophanetetraenes were explored. Insights into the structures of [23]metacyclophanetri- and [24]metacyclophanetetraenes were gained by X-ray crystallographic investigations on various intermediates. A crystallographic analysis of [6.8]3cyclacene revealed a D3h symmetrical structure with planar benzene rings and a formation of tubular structures in the solid state. [source]

Synthesis of azirines containing aldehyde functionality and their utilization as synthetic tools for five membered oxazoles and isoxazoles

Sulagna Brahma
A simple and useful procedure for the synthesis of azirines containing aldehyde functionality from open chain bromo/chloro-aldehydes at room temperature is reported. The scope of the ring expansion reaction of a number of 3-substituted-2-formyl-azirines has been examined using different oraganometallic catalysts and a variety of Lewis acids. [source]

Polyhedral oligomeric silsesquioxane bound fulleropyrrolidines

David J. Clarke
Abstract The first reported examples of polyhedral oligomeric silsesquioxane (POSS) cages containing a fulleropyrrolidine species are reported herein. Monosubstituted POSS-dioxalane species were synthesized through the hydrosilylation of a silyl-dioxalane with mono-vinyl substituted POSS. Subsequent deprotection yielded the desired aldehyde functionality. An alternative synthetic pathway, involving the nucleophilic substitution of mono-benzyl chloride POSS with 4-hydroxybenzaldehyde yielded the desired aldehyde functionality. Each mono-aldehyde POSS was then reacted with N -methylglycine and C60 to yield the desired POSS fulleropyrrolidines. The prepared compounds were characterized by multinuclear NMR, electrospray mass spectrometry, elemental analysis, UV,vis, fluorescence and optical power limiting measurements. Copyright 2008 John Wiley & Sons, Ltd. [source]