253308-76-8Relevant academic research and scientific papers
Asymmetric synthesis of 4-hydroxy-3-phenyltetrahydroisoquinoline derivatives using enantiopure sulfinimines (N-sulfinyl imines)
Davis, Franklin A.,Andemichael, Yemane W.
, p. 8627 - 8634 (2007/10/03)
Addition of lateral lithiated amides and phthalide anions to enantiopure sulfinimines (N-sulfinyl imines) represents a new approach for the asymmetric synthesis of 3-substituted isoquinolones and 3-substituted 4-hydroxy isoquinolones, respectively, important chiral building blocks for isoquinoline alkaloid synthesis. In one example 3-phenylisoquinolone (-)-15b was prepared in >95% ee by treatment of amide ion 10b with sulfinimine (S)- (+)-11 and subsequent deprotection of the N-sulfinyl auxiliary and cyclization. Oxaziridine-mediated hydroxylation of the anion of 16 afforded 4-hydroxy isoquinolone 19, which was transformed into 4-hydroxy-3- phenyltetrahydroisoquinoline (-)-22. In another approach 22 was prepared more directly by addition of phthalide ion 26 to (S)-(+)-11, creating the two stereogenic centers simultaneously. The selectivity proved to be highly counterion dependent.
