Highly efficient and chemoselective interchange of 1,3-oxathioacetals and dithioacetals to acetals promoted by N-halosuccinimide

“…Even acyclic dimethylketals of small-molecule aldehydes and ketones have been obtained by reaction of cyclic dithioketals with methanol or ethanol in the presence of NBS. 22 Although the detailed mechanism of the exchange reaction is unknown, the oxidising character of NBS (effectively a source of Br + ) strongly suggests that the dithiol residue is activated towards replacement by oxidation/halogenation at sulfur. Certainly no thiol-type odours could be detected when working with this type of polymer system.…”

Section: Introductionmentioning

confidence: 99%

Exchange Reactions of Poly(arylene ether ketone) Dithioketals with Aliphatic Diols: Formation and Deprotection of Poly(arylene ether ketal)s

2017

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Article Accepted Version Manolakis, I., Cross, P. and Colquhoun, H. (2017) Exchange reactions of poly(arylene ether ketone) dithioketals with aliphatic diols: formation and deprotection of poly(arylene ether ketal)s. Macromolecules, 50 (24). pp. 95619568. ISSN 00249297 Short title: Exchange reactions of poly(arylene ether ketone) dithioketals with diols ABSTRACT: The dithioketal derivatives of industrially important, semi-crystalline poly(arylene ether ketone)s undergo facile exchange with aliphatic diols in the presence of N-bromosuccinimide to give a range of novel poly(arylene ether ketal)s. These are amorphous and readily soluble in a wide range of organic solvents. Although generally stable under ambient conditions, they undergo rapid and quantitative hydrolysis in the presence of acids to regenerate the original polyketones. The poly(ether ketal)s reported here are not accessible from ketal-type monomers, nor can they be obtained by direct reaction of poly(ether ketone)s with aliphatic diols. The starting polyketones are essentially unchanged after sequential dithioketalization, dithioketalketal exchange, ketal hydrolysis, and re-dithioketalization. Poly(arylene ether ketal)s provide a new approach to the processing of poly(arylene ether ketone)s into carbon fiber composite materials.

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“…4 The fivemembered oxathiolane ring occurs in nucleoside congeners that possess a pronounced antiviral activity. 5 2-Aryl-1,3-oxathiolanes are efficiently converted into 2-aryl-1,4-oxathiane 6 , acetals 7 , monosulfoxides. 8 Cyclic dithio-and oxathioacetals are employed in the reactions involving the ring-expansion 9 or ring-opening 10 of the thioacetal core, as well as an acyl anion equivalent in the carbon-carbon bond-forming reactions.…”

Section: Introductionmentioning

confidence: 99%

Nitroaromatic bis(2-hydroxyethyl)dithioacetals and oxathioacetals using 2-mercaptoethanol in the presence of chlorosilanes

Papernaya¹,

Shatrova²,

Albanov³

et al. 2012

Arkivoc

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Thioacetalization of the nitrobenzaldehydes with 2-mercaptoethanol is easily carried out in the presence of TMSCl and dichlorodimethylsilane without heating and using of additional solvent. The reaction direction is defined by the reagents ratio and led to formation of bis(2-hydroxyethyl)dithioacetals (yield 76-91%) or 1,3-oxathiolanes (yield 76-91%). Bis(2-hydroxyethyl)dithioacetals are easily transformed in the corresponding 1,3-oxathiolanes at long storage without heating or influence of catalysts, and also under electronic and chemical ionization.

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Highly efficient and chemoselective interchange of 1,3-oxathioacetals and dithioacetals to acetals promoted by N-halosuccinimide

Cited by 24 publications

References 22 publications

Five‐Membered Heterocycles with Two Heteroatoms: O and S Derivatives

Five‐Membered Heterocycles with Two Heteroatoms: O and S Derivatives

Exchange Reactions of Poly(arylene ether ketone) Dithioketals with Aliphatic Diols: Formation and Deprotection of Poly(arylene ether ketal)s

Nitroaromatic bis(2-hydroxyethyl)dithioacetals and oxathioacetals using 2-mercaptoethanol in the presence of chlorosilanes

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