Piperidine Framework Research Articles

Studies on Instructive Construction of exo-Olefin Terminated Five- and Six-Membered Nitrogen Heterocycles: SmI2-Mediated Intramolecular Cyclization of Haloalkynals.

Stereoselective construction of exo-olefin terminated pyrrolidine and piperidine frameworks was developed by employing SmI2-mediated intramolecular radical cyclization of haloalkynaks. The radical cyclization affording 2,3-disubstituted pyrrolidines and piperidines proceeded in a highly stereoselective manner. However, decreasing stereoselectivety was observed in the preparation of 2,4-disubstituted pyrrolidine and 3,4-disubstituted piperidine derivatives in the cyclization.

ChemInform Abstract: Catalytic Asymmetric Formal [3 + 3] Cycloaddition of an Azomethine Ylide with 3‐Indolylmethanol: Enantioselective Construction of a Six‐Membered Piperidine Framework.

AbstractFor the first time the enantioselective cycloaddition of isatin‐derived 3‐indolylmethanol is presented realized by an unprecedented formal [3 + 3] cycloaddition of azomethine ylide instead of the common [3 + 2] cycloaddition.

Catalytic Asymmetric Formal [3+3] Cycloaddition of an Azomethine Ylide with 3‐Indolylmethanol: Enantioselective Construction of a Six‐Membered Piperidine Framework

A catalytic asymmetric formal [3+3] cycloaddition of 3-indolylmethanol and an in situ-generated azomethine ylide has been established to construct a chiral six-membered piperidine framework with two stereogenic centers. This approach not only represents the first enantioselective cycloaddition of isatin-derived 3-indolylmethanol, but also has realized an unusual enantioselective formal [3+3] cycloaddition of azomethine ylide rather than its common [3+2] cycloadditions. Besides, this protocol combines the merits of a multicomponent reaction and organocatalysis, which efficiently assembles a variety of isatin-derived 3-indolylmethanols, aldehydes, and amino esters into structurally diverse spiro[indoline-3,4'-pyridoindoles] with one all-carbon quaternary stereogenic center in high yields and excellent enantioselectivities (up to 93 % yield, >99 % enantiomeric excess (ee)). Although the diastereoselectivity of the reaction is generally moderate, most of the diastereomers can be separated by using column chromatography followed by preparative TLC.

Aza-Claisen rearrangement of 2-C-hydroxymethyl glycals as a versatile strategy towards synthesis of isofagomine and related biologically important azasugars

Synthesis of isofagomine has been achieved by implementation of aza-Claisen rearrangement of 2-C-hydroxymethyl glycals as a key step. The above rearrangement has also been utilized in the synthesis of biologically important polyhydroxylated piperidine frameworks such as isogalactofagomine, ent-isogalactofagomine and their analogues and some other azasugars as glycosidase inhibitors.

Organocatalytic Sequential Hetero-Diels–Alder and Friedel–Crafts Reaction: Constructions of Fused Heterocycles with Scaffold Diversity

A highly enantioselective aza-Diels-Alder and Friedel-Crafts reaction sequence of N-sulfonyl-1-aza-1,3-butadienes and aliphatic aldehydes tethered to an arene motif has been developed, affording the fused chiral piperidine frameworks with a versatile scaffold diversity. A similar strategy has been applied for the construction of complex chiral tetrahydroquinoxaline structures.

Synthesis and Antileukemic Activity of Novel 4‐(3‐(Piperidin‐4‐yl) Propyl)Piperidine Derivatives

To explore the anticancer effect associated with the piperidine framework, several (substituted phenyl) {4-[3-(piperidin-4-yl)propyl]piperidin-1-yl} methanone derivatives 3(a-i) were synthesized. Variation in the functional group at N-terminal of the piperidine led to a set of compounds bearing amide moiety. Their chemical structures were confirmed by (1) H NMR, IR and mass spectra analysis. Among these, compounds 3a, 3d and 3e were endowed with antiproliferative activity. The most active compound among this series was 3a with nitro and fluoro substitution on the phenyl ring of aryl carboxamide moiety, which inhibited the growth of human leukemia cells (K562 and Reh) at low concentration. Comparison with other derivative (3h) results shown by LDH assay, cell cycle analysis and DNA fragmentation suggested that 3a is more potent to induce apoptosis.

ChemInform Abstract: Synthesis of Pharmaceutically Active Compounds Containing a Disubstituted Piperidine Framework.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A simple and efficient synthesis of new cyclic ureas

A facile access to a wide range of original saturated N-heterocyclic ureas is described using, as a key step, a Michael-type reaction involving isocyanates or amines on a piperidine framework possessing an α,β-unsaturated ester functionality.

A New Synthetic Approach to 1-[(3 R,4 R)-1-Cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl-1,3-dihydro-benzimidazol-2-one (J-113397), the first non-peptide ORL-1 receptor antagonist

An efficient approach to 1-[(3 R,4 R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl-1,3-dihydro-benzimidazol-2-one (J-113397) 1 , the first non-peptide ORL-1 receptor antagonist described in literature, is outlined. After construction of the piperidine framework through Dieckmann cyclization of the Michael adduct 8 of cyclooctylmethylamine to methyl acrylate, condensation with o-phenylendiamine produced the β-enamino ester 2 , which has been conveniently used to construct the benzimidazolone substituent at C-4. Catalytic hydrogenation of intermediate 11 followed by base-promoted cis– trans isomerization of the key compound 12 led to the formation of ester 13 , which was converted to the racemic title compound by LiAlH 4 reduction. The pure enantiomers were obtained by chiral preparative HPLC separation using a derivatized cellulose-based stationary phase.

Design of a potent 5-HT 4 receptor agonist with nanomolar affinity

It was demonstrated that potent and selective ligands for the 5-HT 4 receptor devoid of 5-HT 3 receptor antagonist properties could be designed from the esters of 4-amino-5-chloro-2-methoxybenzoic acid and the conformationally flexible piperidine framework derived from the locked structure of the quinuclidine ring of zacopride. The compounds were evaluated in binding assays with [ 3H]-GR-113808 and [ 3H]-BRL-43694 and fonctionally using electrically-evoked contractions in the guinea-pig ileum. Coumpound 7 exhibited nanomolar 5-HT 4 receptor agonist activity.

Tandem michael reactions for the construction of pyrrolidine and piperidine ring systems

A convergent one-pot construction of disubstituted pyrrolidine and piperidine frameworks has been accomplished through a simple protocol involving intermolecular conjugate addition of a nitrogen nucleophile to an electrophilic olefin followed by intramolecular trapping of the generated enolate by a built-in α,β,-unsaturated acceptor.