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Asymmetric Synthesis of Isoquinoline Derivatives from Amino Acids
Author(s) -
Sieck Oxana,
Ehwald Max,
Liebscher Jürgen
Publication year - 2005
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200400693
Subject(s) - chemistry , isoquinoline , regioselectivity , stereoselectivity , nucleophile , dimethyldioxirane , ring (chemistry) , amine gas treating , medicinal chemistry , selectivity , organic chemistry , catalysis
Reaction of isoquinolines 1 with N ‐arylsulfonylamino acid fluorides 2 provides a highly stereoselective access to new dihydroimidazo[2,1 ‐a ]isoquinolin‐3‐ones 5 via intermediate N ‐acylisoquinolinium salts 3 . Addition reactions to the en‐amine double bond, such as hydrogenation or epoxidation with dimethyldioxirane, leads to tetrahydroimidazo[2,1 ‐a ]isoquinoline‐3‐ones 6 , 7 and oxiranes 8 , respectively. Opening of the oxirane ring of the 8 with nucleophiles allows the synthesis of hydroxytetrahydroimidazo[2,1 ‐a ]isoquinolin‐3‐ones 10 or 12 or of the polycyclic 1,4‐dioxane 13 in high stereoselectivity. The regioselectivity of the oxiran ring opening depends on the kind of nucleophile and the conditions. Reaction of dihydroisoquinoline with O ‐TBDMS‐mandelic acid chloride 15 leads to a tetrahydrooxazolo[2,3 ‐a ]isoquinoline 17 with opposite facial selectivity as compared with dihydroimidazo[2,1 ‐a ]isoquinolin‐3‐ones 5 . (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)