The selective functionalisation and difunctionalisation of p-substituted calix[6]arene and calix[8]arenes using hydrophilic moieties

Abstract

Methodologies to access water soluble large ringed calixarenes in good yield using efficient synthetic procedures have been investigated. Symmetrical partial functionalisations at the lower rim are described using activated [n]ethylene glycol chains and the addition behaviour contrasted with that of bromoalkanenitriles which proceeds with no observed regioselectivity. Full functionalisations of the calixarenes bearing hydrophilic groups are then investigated and a two-step procedure established which appears to be generally applicable for the addition of different [n]ethylene glycol chains. Furthermore, difunctionalisation under different reaction conditions are described. Throughout, strategies for the characterisation of these high mass compounds are outlined.

Mono- and dicationic short PEG and methylene dioxyalkylglycerols for use in synthetic gene delivery systems

“…The tertiary amines 6-10 were prepared from 3-(dimethylamino)-1,2-propandiol and the corresponding alkyl mesylate as previously described. 34 Synthesis of the unsaturated C 14 (at C-11) C 16 and C 18 mesylates have been reported: 34 the C 14 (at C-9) alkyne and alkene mesylates were readily prepared from the alcohols which were synthesised via a route similar to that recently reported by Basita-Pereira et al 35 Mono-brominations of commercially available PEG diols were achieved using hydrobromic acid 36 or thionyl bromide to give 11-14 in 36-58% yield. Quaternisation of amines 6-10 with PEG bromoalcohols 11-14 in methanol using a sealed tube readily gave the PEGlipid conjugates 15-24 (Scheme 1, Table 1).…”

Multigram Synthesis of Well-Defined Extended Bifunctional Polyethylene Glycol (PEG) Chains

“…Extended homologues are most commonly prepared from shorter, commercially available PEG chains from mono- or difunctionalized derivatives 1 and 2 (Scheme ). This strategy is limited by the availability of monoprotected and bifunctional PEGs ( 1 and 3 ). , As an excess of one of the reactants is needed to maximize the yield of these unsymmetrical PEGs, further extension of the chain length becomes an impractical and expensive exercise. To date, examples of long PEGs are limited to no more than a handful of symmetrical diols H(OCH 2 CH 2 ) n OH, where n = 12, , 13, 14, 18, 28, and 42 .…”

Design and synthesis of fluorescence-labeled nucleotide with a cleavable azo linker for DNA sequencing

“…13 The synthesis of 2,2-dimethyl-4-oxo-3,8,11-trioxa-5-azatridecan-13-yl 4-methylbenzenesulfonate (2) was carried out in a fourstep reaction strategy according to published procedures. [14][15][16][17] The treatment of 2-(4-aminophenyl)ethanol with concentrated hydrochloric acid, sodium nitrite and 4-ethylphenol in water at À5 1C delivered a desired azo intermediate 3 in good yield. The compound 3 was dissolved in DMF, in which potassium carbonate and compound 2 were added.…”