Cobalt-mediated (2 + 2 + 2) cycloadditions of alkynes to the indole 2,3-double bond: an extremely facile entry into the novel 4a,9a-dihydro-9H-carbazole nucleus

Journal Article · Wed Apr 16 04:00:00 EST 1986 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00268a060· OSTI ID:5532618

Grotjahn, D B; Vollhardt, P C

Because of the extremely diverse physiological activity exhibited by the indole nucleus and its presence in a multitude of natural products selective alteration of its structure has commanded a considerable amount of synthetic attention. Part of this effort has involved the utilization of the 2,3-double bond in Diels-Alder and other cycloadditions. The authors report a novel mode of reactivity of this bond in the presence of eta-CpCo reagents: the (2 + 2 + 2) cycloaddition to two alkynes to provide the hitherto unknown 4a,9a-dihydro-9H-carbazole nucleus as incorporated in a variety of complex polycyclic dienes. This methodology demonstrates for the first time the feasibility of activating aromatic double bonds in CpCo-mediated cyclizations and provides a powerful means by which to fuse several rings onto the indole moiety in one step.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 5532618
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 108:8; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ALKYNES
AROMATICS
AZAARENES
AZOLES
CARBAZOLES
CHEMICAL BONDS
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COBALT
DATA
DOUBLE BONDS
ELEMENTS
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
INDOLES
INFORMATION
METALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRROLES
SYNTHESIS
TRANSITION ELEMENTS