CARBON DOIXIDE: A REAGENT FOR THE PROTECTION OF NUCLEOPHILIC CENTERS AND THE SIMULTANEOUS ACTIVATION OF ELECTROPHILIC ATTACK. PART II. A NEW SYNTHETIC METHOD FOR THE 1-SUBSTITUTION OF 1,2,3,4-TETRAHYDROISOQUINOLINES.

Article abstract of DOI:10.1016/0040-4020(86)80024-2

Tetrahydroisoquinoline was converted into several 1-substituted derivatives by using carbon dioxide both for N-protection and to give an intermediate carbanion stabilizing group. t-Butyllithium was used as a lithating agent at the alpha-carbon atom of the secondary amino group.The resulting 1-substituted 1,2,3,4-tetrahydroisoquinoline-2-carboxylic acids underwent smooth acid-catalysed decarboxylation under mild conditions.