1659-31-0Relevant articles and documents
Functional mimicry of the active site of carboxypeptidase A by a molecular imprinting strategy: Cooperativity of an amidinium and a copper ion in a transition-state imprinted cavity giving rise to high catalytic activity
Liu, Jun-Qiu,Wulff, Guenter
, p. 7452 - 7453 (2007/10/03)
A model for the natural enzyme carboxypeptidase A was prepared by molecular imprinting in synthetic polymers. An unusually high activity and efficiency for carbonate hydrolysis could be obtained by imprinting with a stable transition-state analogue template and introducing an amidinium group and a Cu2+ ion-binding site in a defined orientation to each other into the active site. With substrates having a very similar structure to the template, extraordinarily high enhancements of rates of 110000-fold were obtained of catalyzed to uncatalyzed reaction kcat/kuncat. The efficiency kcat/Km of the molecularly imprinted catalysts compared to that of the nonimprinted control polymers containing the same functional groups was 790-fold higher, a clear indication of a very efficient imprinting procedure. Copyright
Amino acid derivatives as paf-receptor antagonists
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, (2008/06/13)
Compounds of general formula I: STR1 wherein W represents imidazo [4,5-c]pyridin-1-yl, imidazo [4,5-c]pyridin-3-yl and imidazo [4,5-c]pyridin-5-yl optionally substituted with one or more --C1 -C6 alkyl substituents; Z represents a) a divalent alkanediyl, alkenediyl or alkynediyl group; b) a --(CH2)q U(CH2)r -- group, optionally substituted, wherein q is an integer from 0-3, r is an integer from 0-3 and U is --O-- or --S--; Q represents a carbonyl, thiocarbonyl or sulphonyl group; B represents a) a --VR8 group wherein V is --C(=O)O-- or --CH2 O--; are antagonists of platelet activating factor (PAF).
Di(2-pyridyl) carbonate promoted alkoxycarbonylation of amines: A convenient synthesis of functionalized carbamates
Ghosh, Arun K.,Duong, Tien T.,McKee, Scan P.
, p. 4251 - 4254 (2007/10/02)
The reaction of di(2-pyridyl) carbonate with a variety of alcohols including hindered secondary, tertiary and protected glycols afforded the corresponding mixed carbonate which was efficiently transformed into various carbamates in high yield under mild c
2(1H)-Pyridone as Leaving Group in Acylation Reactions - Applications in Peptide Synthesis
Effenberger, Franz,Brodt, Werner
, p. 468 - 482 (2007/10/02)
Alkyl 2-pyridyl carbonates 3 or mixtures of 3 and the isomeric N-(alkoxycarbonyl)-2-pyridones 3' are useful for the introduction of urethane protective groups into amino acids.The N-protected amino acids 7 - 10 react with 2(1H)-pyridone (1a) using the carbodiimide method to yield 2-pyridyl active esters 11, which easily undergo coupling reactions with amino acid esters 12 with elimination of 1a to give peptides 13 in good yields as well as high optical purities.
New Amino-protective Reagents for t-Butoxycarbonylation and Benzyloxycarbonylation of Amines and Amino Acids
Kim, Sunggak,Lee, Jae In,Yi, Kyu Yang
, p. 3570 - 3575 (2007/10/02)
New amino-protective reagents for t-butoxycarbonylation and benzyloxycarbonylation of amines and amino acids have been developed. t-Butyl 2-pyridyl carbonate and t-butyl S-(2-pyridyl) thiocarbonate react cleanly with various amines and amino acids to afford N-Boc amines and N-Boc amino acids in high yields.Benzyl 2-pyridyl carbonate and O-benzyl S-(2-pyridyl) thiocarbonate are also found to be very effective in the benzyloxycarbonylation of amino acids.
DI-2-PYRIDYL CARBONATE: A NEW EFFICIENT COUPLING AGENT FOR THE DIRECT ESTERIFICATION OF CARBOXYLIC ACIDS
Kim, Sunggak,Lee, Jae In,Ko, Young Kwan
, p. 4943 - 4946 (2007/10/02)
Reaction of carboxylic acids with equimolar amounts of di-2-pyridyl carbonate and alcohols or thiols in the presence of 4-dimethylaminopyridine as a catalyst in methylene chloride at room temperature affords the corresponding esters in high yields under mild conditions.