A new 2‐oxazoline monomer with a protected thiol group, 2‐[2‐(4‐methoxybenzylsulfanyl)ethyl]‐2‐oxazoline, MOB‐SOx, was synthesized from commercially available compounds. MOB‐SOx and 2‐ethyl‐2‐oxazoline (EtOx) were simultaneously polymerized yielding well defined copolymers with narrow molar mass distributions and target polymer chain length. The copolymerization was initiated by N‐methyl‐2‐methyl‐2‐oxazolinium triflate (MeOxOTf). After quantitative deprotection, poly(2‐oxazoline) with pendant thiol groups was obtained. The thiol groups were quantitatively added to the double bond of N‐phenyl‐acrylamide (PhA) and benzylmaleimide (BzM). Graft copolymers were obtained by reaction of those SH containing polymers with poly(2‐methyl‐2‐oxazoline)s bearing acrylamide (PMeOx10A) and maleimide (PMeOx10M) as terminal reactive groups.magnified image

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The methodology of enantioselective decarboxylation was applied to 2‐aminomalonic acid derivatives in order to obtain enantio‐enriched amino acid derivatives. Full conversion was achieved stirring racemic N‐acetylated 2‐aminomalonic hemiesters in THF at 70 °C with 10 mol % of a chiral base for 24 h. The catalyst may be recycled. Whereas the commercially available cinchona alkaloids gave poor results, benzamide and benzenesulfonamide derivatives of 9‐amino(9‐deoxy)epicinchonine turned out to be effective catalysts. The best result was obtained with 2‐N‐acetylamino‐2‐ethoxycarbonyl‐3‐phenylpropionic acid as the starting material and N‐(9‐deoxyepicinchonine‐9‐yl)‐4‐methoxybenzamide as the chiral base to give ethyl N‐acetyl‐L‐phenylalaninate in 70% ee. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)