Synthesis of Novel 1,2,3,4-Tetrahydroisoquinoline-3-carboxylic Acid Derivatives through the Application of Rongalite: A Synergistic Combination of [2+2+2]- and [4+2]-Cycloaddition Reactions - Kotha, Sambasivarao; Banerjee, Shaibal (Synthesis, 2007)