Over four hundred alkaloids in amphibian skin have been detected and structures from twenty different classes have been elucidated. These include batrachotoxins, histrionicotoxins, pumiliotoxins, epibatidine, pyrrolidines, piperidines, decahydroquinolines, pyrrolizidines, indolizidines, quinolizidines and tricyclic gephyrotoxins, pyrrolizidine oximes, pseudophrynamines, coccinellines and cyclop...

A general chemo-enzymatic approach to synthesize both enantioenriched trans-3-alkoxyamino-4-oxy-2-piperidones, which are important scaffold for various naturally occurring alkaloids, is reported. To this end, a selective transition-metal-free dual C−H oxidation of piperidines mediated by the TEMPO oxoammonium cation (TEMPO+) was used, followed enzymatic resolution corresponding alkoxyamino-2-pi...

Piperazine ranks within the top three most utilized N-heterocyclic moieties in FDA-approved small-molecule pharmaceuticals. Herein we summarize the current synthetic methods available to perform C-H functionalization on piperazines in order to lend structural diversity to this privileged drug scaffold. Multiple approaches such as those involving α-lithiation trapping, transition-metal-catalyzed...

QSAR study describes the anti-neoplastic spiro-alkaloids with relevant molecular descriptors using CODESSA III software. The dispiro[3H-indole-3,2'-pyrrolidine-3',3"-piperidines] 24-48 were synthesized via [3 + 2]-cycloaddition reaction of azomethine ylides, (generated in situ via decarboxylative condensation of isatins 21-23 with sarcosine) and 3E,5E-1-alkyl-3,5-bis(arylmethylidene)-4-piperido...

This account focuses on the application of ω-transaminases, lyases, and oxidases for the preparation of amines considering mainly work from our own lab. Examples are given to access α-chiral primary amines from the corresponding ketones as well as terminal amines from primary alcohols via a two-step biocascade. 2,6-Disubstituted piperidines, as examples for secondary amines, are prepared by bio...

synthesis and characterization of two functionalized gold nanoparticles by using of two poly functional amino acids (l-arginine and l-aspartic acid) are reported. the gold nanoparticles were reduced by sodium citrate and functionalized with l-arginine at the ph of 7 and 11 and l-aspartic acid at the ph of 7. transmission electron microscopy, uv-vis spectroscopy, dynamic light scattering, zeta p...

toluene and benzene were eliminated using multi-walled carbon nanotubes (mwcnts). in order to investigate influence of acid treatment on the mwcnts adsorption capacities, the mwcnts were functionalized by nitric acid (10 m) under reflux conditions for 2 h. fourier transform infrared (ftir) and raman spectroscopy were employed to confirm the formation of functional groups on the nanotubes surfac...