Construction of nitrogen bicyclic and cage compounds with the use of allylic organoboranes*
Yu. N. Bubnov1,2, N. Yu. Kuznetsov1, M. E. Gurskii2, A. L. Semenova2, G. D. Kolomnikova1, and T. V. Potapova2
1A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova str., 119991 Moscow, Russian Federation; 2N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation
Abstract: It is shown that reactions of triallylborane with pyrrole, pyridines, isoquinolines, lactams, 1-pyrroline, and acetylenes offer versatile methodology for the construction of various bicyclic and polycyclic nitrogen compounds, some of which are skeletally related to important classes of alkaloids. Optically active 3-borabicyclo[3.3.1]non-6-enes are useful precursors for synthesis of chiral 3-aza- and 3-thiabicyclo[3.3.1]non-6-enes, as well as derived chiral cyclohexenoid systems. The convenient methodology for the transformation of 1-boraadamantanes into 1-azaadamantanes is also discussed.
Keywords: nitrogen bicyclic compounds; nitrogen cage compounds; allylic organoboranes; alkaloid synthesis; chiral cyclohexene derivatives; boraadamantanes; azaadamantanes.
*Paper based on a presentation at the 12th International Meeting on Boron Chemistry (IMEBORON-XII), Sendai, Japan, 11-15 September 2005. Other presentations are published in this issue, pp. 1299-1453.