Synthesis and conformational analysis of tetrahydroisoquinoline- and piperidine-fused 1,3,4,2-oxadiazaphosphinanes, new ring systems

Autor: László Lázár, Tamás A. Martinek, Zita Zalán, Reijo Sillanpää, Ferenc Fülöp
Rok vydání: 2006
Předmět:
Zdroj: Tetrahedron. 62:2883-2891
ISSN: 0040-4020
DOI: 10.1016/j.tet.2006.01.018
Popis: Through cyclization of tetrahydroisoquinoline and piperidine 1,2-hydrazino alcohols with phenylphosphonic dichloride and phenyl dichlorophosphate, P-epimeric diastereomers of 1,6,7,11b-tetrahydro-4H-1,3,4,2-oxadiazaphosphino[5,4-a]isoquinoline-3-oxides ( 13 and 14 ), 1,6,11,11a-tetrahydro-4H-1,3,4,2-oxadiazaphosphino[4,5-b]isoquinoline-3-oxides ( 15 and 16 ) and 1,6,7,8,9,9a-hexahydro-4H-pyrido[1,2-d][1,3,4,2]oxadiazaphosphinane-3-oxides ( 17 and 18 ), the first representatives of these ring systems, were prepared. NMR and X-ray diffraction studies revealed that, independently of the P-substituent and the relative configuration of the phosphorus atom, 13 , 14 , 17 and 18 could be characterized by trans-connected hetero rings and the chair conformation of the 1,3,4,2-oxadiazaphosphinane moiety, while the stereochemistry of the connection of the hetero rings in the 1,3,4,2-oxadiazaphosphinanes linearly fused to tetrahydroisoquinoline ( 15 and 16 ) was found to be dependent on the P-configuration relative to that of the carbon at the annelation.
Databáze: OpenAIRE