639458-47-2Relevant articles and documents
Kinetic resolution of secondary alcohols using amidine-based catalysts
Li, Ximin,Jiang, Hui,Uffman, Eric W.,Guo, Lei,Zhang, Yuhua,Yang, Xing,Birman, Vladimir B.
experimental part, p. 1722 - 1737 (2012/04/04)
Kinetic resolution of racemic alcohols has been traditionally achieved via enzymatic enantioselective esterification and ester hydrolysis. However, there has long been considerable interest in devising nonenzymatic alternative methods for this transformation. Amidine-based catalysts (ABCs), a new class of enantioselective acyl transfer catalysts developed in our group, have demonstrated, inter alia, high efficacy in the kinetic resolution of benzylic, allylic, and propargylic secondary alcohols and 2-substituted cycloalkanols, and thus provide a viable alternative to enzymes.
Stereoselective asymmetric synthesis of (+)-sedamine and (+)-allosedamine
Lebrun, Stephane,Couture, Axel,Deniau, Eric,Grandclaudon, Pierre
experimental part, p. 212 - 216 (2010/11/18)
A convenient method for the generation of (+)-sedamine and (+)-allosedamine in high optical purity has been elaborated. The key steps are the highly stereoselective 1,2-nucleophilic addition to SAMP hydrazones allowing the installation of the stereogenic center at C2 and ring closing metathesis.
Asymmetric synthesis of Sedum alkaloids via lithium amide conjugate addition
Davies, Stephen G.,Fletcher, Ai M.,Roberts, Paul M.,Smith, Andrew D.
experimental part, p. 10192 - 10213 (2010/02/28)
Conjugate addition of lithium (R)-N-allyl-N-(α-methylbenzyl)amide or lithium (R)-N-but-3-enyl-N-(α-methylbenzyl)amide to an alkyl hexa-2,4-dienoate or alkyl hepta-2,6-dienoate, followed by ring-closing metathesis of the olefin functionalities within the resultant β-amino ester, generates a range of diastereoisomerically pure azacycles in good yield. These homochiral templates are readily transformed to a range of piperidine alkaloids of the Sedum family, and the corresponding five-, seven- and eight-membered ring homologues.
Enantioselective organocatalytic intramolecular aza-Michael reaction: A concise synthesis of (+)-sedamine, (+)-allosedamine, and (+)-coniine
Fustero, Santos,Jimenez, Diego,Moscardo, Javier,Catalan, Silvia,Del Pozo, Carlos
, p. 5283 - 5286 (2008/09/18)
(Chemical Equation Presented) The intramolecular aza-Michael reaction of carbamates bearing remote α,β-unsaturated aldehydes under organocatalytic conditions took place with good yields and excellent ee's when Jorgensen catalyst IV was used in the process, giving rise to the enantioselective formation of several five- and six-membered heterocycles. The developed methodology was applied to the synthesis of three piperidine alkaloids.
Remote Stereocenter Discrimination in the Enzymatic Resolution of Piperidine-2-ethanol. Short Enantioselective Synthesis of Sedamine and Allosedamine
Angoli, Marco,Barilli, Alessio,Lesma, Giordano,Passarella, Daniele,Riva, Sergio,Silvani, Alessandra,Danieli, Bruno
, p. 9525 - 9527 (2007/10/03)
Kinetic resolution of N-Boc-piperidine-2-ethanol (2), a case of remote stereocenter discrimination, was accomplished by sequential transesterification mediated by two enzymes, Lipase PS and porcine pancreatic lipase, showing opposite enantioselectivity. The gram-scale availability of the two enantiomeric N-Boc alcohols 2a (R) and 2c (S) enlarges their synthetic exploitation for the enantioselective preparation of piperidine alkaloids. As an example, the convenient three-step synthesis of both the enantiomers of sedamine and allosedamine is described.
