Using the bulk chemical 1,4-butynediol, readily available epoxides and carbon dioxide, a new series of unsubstituted exovinylene carbonates were synthesised.

der scharffe Sebel ist mein Acker... U n i v e r s i t ä t P o t s d a mMathematisch-Naturwissenschaftliche Fakultät

A straight‐forward approach to separate catalyst from the exo‐vinylene carbonate (EVC) products of the carboxylative cyclisation of primary propargylic alcohols has been developed. The liquid‐liquid phase synthesis utilises lipophilic silver(I) carboxylate salts and N,N‐dioctyl modified phosphine (FatPhos) ligands to enhance catalyst solubility in non‐polar solvents. Following simple liquid‐liquid phase separation, EVCs relevant as monomers for poly(urethane) and poly(carbonate) synthesis were isolated in the non‐miscible polar phase in good yields. In situ reaction monitoring by ReactIR gave insights into the reaction kinetics and informed the conditions used to afford good EVC selectivity. Under optimised conditions, silver leaching into the product phase was very minor as confirmed by ICP‐MS. Furthermore, a protocol for catalyst recycling by liquid‐liquid separation was demonstrated, with modest loss of catalytic activity over 3 runs.

h) No difference, however, is found if the spacer-free lipid 1 is used for these experiments. This lipid does not show any specific interaction with streptavidiu under the given conditions. Its surface-pressurearea diagrams with free and titrated streptavidin are identical. This indicates that the binding of biotin to the protein does not change its unspecific adsorption characteristics. 464.[21] P. Meller, Rev. Sci. Znstrum. 59 (1988) 2225.[22] M.

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