6202-07-9Relevant articles and documents
Ligand-controlled regiodivergent nickel-catalyzed annulation of pyridones
Donets, Pavel A.,Cramer, Nicolai
, p. 633 - 637 (2015/03/04)
The 1,6-annulated 2-pyridone motif is found in many biologically active compounds and its close relation to the indolizidine and quinolizidine alkaloid core makes it an attractive building block. A nickel-catalyzed C-H functionalization of 2-pyridones and subsequent cyclization affords 1,6-annulated 2-pyridones by selective intramolecular olefin hydroarylation. The switch between the exo- and endocyclization modes is controlled by two complementary sets of ligands. Irrespective of the ring size, the regioselectivity during the cyclization is under full catalyst control. Simple cyclooctadiene promotes an exo-selective cyclization, whereas a bulky N-heterocyclic carbene ligand results in an endoselective mode. The method was further applied in the synthesis of the lupin alkaloid cytisine.
1-Acyldeoxyvasicinone salts as effective intermediate C- and N-acylating agents for alkaloids and amino acids
Shakhidoyatov,Genjemuratova,Oripov
, p. 718 - 723 (2008/02/08)
The reaction of deoxyvasicinone with acid chlorides of aliphatic (acetylbromide) and aromatic (benzoyl-, o-, p-methoxy-, p-nitrobenzoylchlorides) acids was studied. It was shown that 1-deoxyvasicinone salts were formed at room temperature; α-aroyloxymethylidenedeoxyvasicinones, in the presence of triethylamine at 80-85°C. It was found that acid chlorides cause 1-acyldeoxyvasicinone salts to transform into α-hydroxy-or α-aroyloxyarylidenedeoxyvasicinones, which indirectly confirmed their acylating properties. It was found that 1-acyldeoxyvasicinone salts were effective acylating agents for alkaloids (cytisine, 1,2-dihydrodeoxyvasicinone) and amino acids (glycine, β-alanine, α-aminobutyric acid) and can be used to acylate primary and secondary aliphatic and heterocyclic amines.
Regio- and diastereoselective functionalization of (-)-cytisine: An unusual N-C acyl migration
Rouden, Jacques,Ragot, Alexis,Gouault, Sonia,Cahard, Dominique,Plaquevent, Jean-Christophe,Lasne, Marie-Claire
, p. 1299 - 1305 (2007/10/03)
In order to test (-)-cytisine as a potential chiral inductor, N-propionyl cytisine was treated with LDA and then with benzyl bromide. Instead of the expected α-benzyl substituted propionamide, (-)-N-benzyl 6α-propionyl cytisine was formed, arising from an