Facile transformation of 2-azetidinones to 2-piperidones: application to the synthesis of the indolizidine skeleton and (8S,8aS)-perhydro-8-indolizinol

Interrupted Pyridine Hydrogenation: Asymmetric Synthesis of δ-Lactams

Metal-catalyzed hydrogenation is an effective method to transform readily available arenes into saturated motifs, however, current hydrogenation strategies are limited to the formation of C-H and N-H bonds. The stepwise addition of hydrogen yields reactive unsaturated intermediates that are rapidly reduced. In contrast, the interruption of complete hydrogenation by further functionalization of unsaturated intermediates offers great potential for increasing chemical complexity in a single reaction step. Overcoming the tenet of full reduction in arene hydrogenation has been seldom demonstrated. In this work we report the synthesis of sought-after, enantioenriched δ-lactams from oxazolidinone-substituted pyridines and water by an interrupted hydrogenation mechanism.

Stereoselective Synthesis of Highly Functionalized 5- and 6-Membered Aminocyclitols Starting with a Readily Available 2-Azetidinone

Stereoselective transformations of 4-vinyl-2-azetidinone derivative 4 into a variety of highly functionalized 6- and 5-membered carbocyclic compounds 7 and 9 were carried out using sequences involving sequential C1-N bond cleavage and Ru-catalyzed ring-closing metathesis. The derived carbocycles were further transformed into polyhydroxylated 6- and 5-membered aminocyclitols.

A novel piperazine linked β-amino alcohols bearing a benzosuberone scaffolds as anti-proliferative agents

A new series of 1-((9-chloro-2,3-dimethyl-6,7-dihydro-5H-benzo[7]annulen-8-yl)methoxy)-3-(4-phenylpiperzin-1-yl) propan-2-ols (6a-k) have been designed, synthesized and their structures were established by spectroscopic data (FT-IR, ¹H NMR, ¹³C NMR, HRMS) and further confirmed by X-ray analysis. The newly synthesized compounds 6a-k were evaluated for their in vitro anti-proliferative activity against four cancer cell lines such as HeLa (cervical), MDA-MB-231 (breast), A549 (lung) and MIAPACA (pancreatic). Among the compounds tested, the compound 6e displayed most potent activity against four cancer cell lines with GI₅₀ values ranging from 0.010 to 0.097μM. The structure and anti-proliferative activity relationship was further supported by in silico molecular docking study of the active compounds against Colchicine binding site of β-tubulin.

Regio- and diastereocontrolled C–H insertion of chiral γ- and δ-lactam diazoacetates. Application to the asymmetric synthesis of (8S,8aS)-8-hydroxyindolizidine

gamma- and delta-Lactam diazoacetates undergo efficient intramolecular C-H insertion catalyzed by Rh2(MPPIM)4 with excellent regioselectivity and cis-diastereoselectivity to provide synthetically useful bicyclic lactam lactones.

A General Approach to (5S,6R)-6-Alkyl-5-benzyloxy-2-piperidinones: Application to the Asymmetric Syntheses of Neurokinin Substance P Receptor Antagonist (−)-L-733,061 and (−)-Deoxocassine

A general approach to (5S,6R)-6-alkyl-5-benzyloxy-2-piperidinones based on the regio- and diastereoselective reductive alkylation of (S)-3-benzyloxyglutarimide 7 is described. This method opens an entrance to chiral nonracemic substituted 3-piperidinols. The versatility of the method is illustrated by the asymmetric syntheses of neurokinin substance P receptor antagonist L-733,061 (ent-1), (-)-deoxocassine (4), and an inhibitor of HIV proteases (5a).