1. For reviews on the various total syntheses of the tetrahydroisoquinoline and tetrahydro-β-carbolines series, see: T.Kametain, in Total Synthesis of Natural Products, ed. J. ApSimon, Wiley, New York, 1977, vol. 3, pp. 1–272;
2. J. P. Kutney , in Total Synthesis of Natural Products, ed. J. ApSimon, Wiley, New York, 1977, vol. 3, pp. 273–288.
3. T. Highsmith and A. I.Meyers, ‘Asymmetric Synthesis of Alkaloids: The α-Alkylation of Nitrogen Heterocycles via Formamidine-Mediated Chiral Carbanions,’ in Advances in Heterocyclic Natural Product Synthesis, JAI Press, Greenwich, 1991;
4. Application of a modified Pictet–Spengler reaction to the synthesis of optically active tetrahydro-β-carbolines, key intermediates in the preparation of many indole alkaloids