Author(s)

M. Nicoletti, D. O'Hagan, A. M. Z. Slawin

ISBN

1472-7781

Publication year

2002

Periodical

Journal of the Chemical Society-Perkin Transactions 1

Periodical Number

1

Volume

Pages

116-121

Author Address

Full version

The Bischler-Napieralski reaction, which is used to prepare dihydroisoquinolines from phenylethylamides, is demonstrated by the reaction of (S)-1-alkyl-1,2-diphenylethylamides with POCl3-P2O5. The reaction generated 3-alkyl-4-phenyl-1,2-dihydroisoquinolines with stereochemical selectivities of 80-91% de depending on the alkyl and the acetamide substituents. These are the rst examples of the asymmetric Bischler-Napieralski reaction where cyclisation discriminates between two identical diastereotopic aryl groups. Reduction of the resultant dihydroisoquinoline products with LiAlH4 generated the corresponding 1,2,3,4-tetrahydroisoquinolines in a stereoselective manner, carrying three stereogenic centres at C(1), C(3) and C(4).