458-88-8Relevant articles and documents
Lewis Acid-Mediated S(N)2 type displacement by grignard reagents on chiral perhydropyrido[2,1-b]pyrrolo[1,2-d][1,3,4]oxadiazine. Chirality induction in asymmetric synthesis of 2-Substituted piperidines
Yamazaki, Naoki,Kibayashi, Chihiro
, p. 4623 - 4626 (1997)
Et2AlCl-mediated nucleophilic alkylation with Grignard reagents on chiral perhydropyrido[2,1-b]pyrrolo[l,2-d][1,3,4]oxadiazine has proved to proceed via an S(N)2 mechanism at low temperatures (below -80°C) with high to excellent inversive stereoselection, while, at an elevated temperature, hydrazonium ions are formed preferentially leading to retentive stereoselection. This methodology provides useful access to enantioselective preparation of 2-substituted piperidines and is used for asymmetric synthesis of (+)-coniine.
Bisnucleophilic substitution as a synthetic tool for ready access to the piperidine alkaloids (+)-Connine, (+)-β-conhydrine, (+)-8-ethylnorlobelol, and (-)-halosaline
Raju, Galla,Anitha, Kadimi,Krishna, Palakodety Radha
, p. 937 - 941 (2015/04/27)
Herein we report the stereoselective total synthesis of (+)-connine, (+)-β-conhydrine, (+)-8-ethylnorlobelol, and (-)-halosaline via bisnucleophilic substitution with benzylamine as the key step.
Characterization of three novel enzymes with imine reductase activity
Gand,Müller,Wardenga,H?hne
, p. 126 - 132 (2015/02/19)
Imine reductases (IRED) are promising catalysts for the synthesis of optically pure secondary cyclic amines. Three novel IREDs from Paenibacillus elgii B69, Streptomyces ipomoeae 91-03 and Pseudomonas putida KT2440 were identified by amino acid or structural similarity search, cloned and recombinantly expressed in E. coli and their substrate scope was investigated. Besides the acceptance of cyclic amines, also acyclic amines could be identified as substrates for all IREDs. For the IRED from P. putida, a crystal structure (PDB-code 3L6D) is available in the database, but the function of the protein was not investigated so far. This enzyme showed the highest apparent E-value of approximately Eapp = 52 for (R)-methylpyrrolidine of the IREDs investigated in this study. Thus, an excellent enantiomeric purity of >99% and 97% conversion was reached in a biocatalytic reaction using resting cells after 24 h. Interestingly, a histidine residue could be confirmed as a catalytic residue by mutagenesis, but the residue is placed one turn aside compared to the formally known position of the catalytic Asp187 of Streptomyces kanamyceticus IRED.