Synthesis of Long Chain Brønsted Acidic Ionic Liquids

Abstract

With the depletion of petroleum, a new source of feedstock chemicals for polymers is needed. The new source should be a renewable source to avoid future depletion and environmental impact. A potential source of new feedstock chemicals is chitin. The use of ionic liquids for the dissolution of chitin has enabled new processing methods for this biopolymer. Recent results demonstrate that chitin can be depolymerizes in ionic liquid. The products of this depolymerization are N-acetylglucosamine and a furfural derivative. This research investigates the use of ionic liquids and various acid catalysts for the depolymerization of chitin into its monomer units. This research evaluates the effects of temperature, the nature of the catalyst, and solvent effects on the depolymerization of chitin.

Structural and Functional Analysis of Bacterial Sulfonosphingolipids and Rosette‐Inducing Factor 2 (RIF‐2) by Mass Spectrometry‐Guided Isolation and Total Synthesis

“…Boc‐deprotected capnine base 13 a was coupled with fatty acid 8 using peptide coupling conditions (HBTU in DMF) to yield 25 a , followed by the introduction of a thioacetate at C‐1 under Mitsunobu conditions in good overall yield. [6]] To allow for mild oxidation conditions, acetate protected thiol was deprotected with NaSMe [34] and then oxidized with m‐ CPBA in a one‐pot fashion at 0 °C, which caused the simultaneous TBS‐deprotection of the secondary alcohol yielding 26 a [35] . Although TBS‐cleavage was preferred under the given reaction conditions, additional TIPS‐deprotection (2’‐position) was observed occasionally with prolonged reaction times.…”

“…[6]] To allow for mild oxidation conditions, acetate protected thiol was deprotected with NaSMe [34] and then oxidized with m-CPBA in a one-pot fashion at 0 °C, which caused the simultaneous TBS-deprotection of the secondary alcohol yielding 26 a. [35] Although TBScleavage was preferred under the given reaction conditions, additional TIPS-deprotection (2'-position) was observed occasionally with prolonged reaction times. With propargyl alcohols Chemistry-A European Journal of type 26 in hands, the selective reduction of the triple bond was performed with Red-Al® and the remaining TIPS-groups were then removed with TBAF in THF.…”