Indole-derived arynes and their Diels-Alder reactivity with furans.
Arynes derived from any position of the ubiquitous indole nucleus are unknown. We have now provided the first evidence for the formation and trapping of the 4,5-, 5,6-, and 6,7-indolynes. A series of o-dihalo indoles (Cl, Br, F) were synthesized and reacted under metal-halogen exchange conditions to give Diels-Alder cycloadducts in high yield with furan. The use of an excess of tert-butyllithium resulted in the rearrangement of the initially formed cycloadduct; however, employing only a slight excess of n-butyllithium cleanly gave cycloadducts with furan.
Buszek
Keith R
KR
Department of Chemistry, Kansas State University, 111 Willard Hall, Manhattan, Kansas 66506, USA. buszekk@umkc.edu
Luo
Diheng
D
Kondrashov
Mikhail
M
Brown
Neil
N
VanderVelde
David
D
D000480:Alkynes / Q000737:chemistry*; D001555:Benzene Derivatives / Q000737:chemistry*; D005663:Furans / Q000737:chemistry*; D006574:Heterocyclic Compounds, 2-Ring / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
D000480:Alkynes; D001555:Benzene Derivatives; D005663:Furans; D006574:Heterocyclic Compounds, 2-Ring; D007211:Indoles; C524146:benzyne