1450932-45-2Relevant academic research and scientific papers
Further investigations into the regioselectivity of 6,7-indole aryne cyclo-additions with 2-substituted furans: Remarkable contrasteric preference depends on pyrrole and benzene ring substitution
Nerurkar, Alok,Chandrasoma, Nalin,Maina, Lincoln,Brassfield, Allen,Luo, Diheng,Brown, Neil,Buszek, Keith R.
, p. 1843 - 1852 (2013/07/26)
A series of related 6,7-dibromoindole compounds were prepared to study the effects of pyrrole and benzene ring substitution patterns on the regioselectivity of 6,7-indole aryne cycloadditions with 2-tert-butylfuran. The arynes were generated by our metal-halogen exchange/elimination protocol. The results of this investigation reveal that substitution at the 3-position on the indole ring in particular results in remarkable regiocontrol that favored the contrasteric products. Aromatic conjugation at this site significantly enhanced this effect. However, the presence of most 4- or 5-substituents generally resulted in markedly reduced selectivity. Exceptions in this latter series included the 4-ethyl and 4-iodo cases both of which also gave predominantly contrasteric products even in the absence of a beneficial C-3 substituent. Georg Thieme Verlag Stuttgart · New York.
