908856-35-9Relevant academic research and scientific papers
Stereodivergent synthesis of hetero-fused isoquinolines by acyliminium and metallation methods
Osante, I?aki,Collado, M. Isabel,Lete, Esther,Sotomayor, Nuria
, p. 1267 - 1277 (2007/10/03)
Diastereodivergent syntheses of 1,10b-cis- and 1,10b-transthiazolo[4,3-a]isoquinoline systems are reported. The key transformations are based on the intramolecular cyclization of aryllithiums and N-acyliminium ions. With 5-substituted N-phenethylthiazolidinediones as substrates, hydride reduction or the organolithium addition-N-acyliminium cyclization sequence stereoselectively afforded the l, 10b-cis derivatives. Alternatively, the tandem Parham cyclization-hydroxyl reduction using the corresponding iodinated thiazolidinediones occurred with complete control of stereoselectivity, producing the 1,10b-trans diastereomers. Although it was not possible to synthesise imidazo[4,3-a]isoquinolinones by N-acyliminium cyclizations, application of the Parham cyclization-reduction sequence to N-phenethylhydantoins constituted an efficient alternative for the synthesis of these hetero-fused isoquinolines with 1,10b-trans stereochemistry. Ready access to 1-phenethylisoquinolines is also described.
Diastereodivergent approaches to thiazolo[4,3-a]isoquinoline systems via Parham-type and N-acyliminium ion cyclizations
Osante, I?aki,Collado, M. Isabel,Lete, Esther,Sotomayor, Nuria
, p. 101 - 103 (2007/10/03)
Diastereodivergent approaches to thiazolo[4,3-a]isoquinoline systems are described. The sequence reduction - N-acyliminium cyclization of 1- substituted N-phenethylthiazolidinediones afforded stereoselectively the 1,10b-cis derivatives. Alternatively, the tandem Parham cyclization - hydroxyl reduction on the corresponding iodinated thiazolidinediones occurred with complete control of stereoselectivity, leading to the 1,10b-trans diastereomers. Typical yields of the resulting thiazolo[4,3-a]isoquinolines ranged 66-92% with facial diastereoselectivities of >95:5.
