Synlett 2017; 28(14): 1738-1742
DOI: 10.1055/s-0036-1588503
cluster
© Georg Thieme Verlag Stuttgart · New York

Base-Induced Cyclisation of ortho-Substituted 2-Phenyloxazolines to Give 3-Aminobenzofurans and Related Heterocycles

EaStCHEM School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK   eMail: raa@st-and.ac.uk
,
Andrew D Harper
EaStCHEM School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK   eMail: raa@st-and.ac.uk
,
Alexandra M. Z. Slawin
EaStCHEM School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK   eMail: raa@st-and.ac.uk
› Institutsangaben
We thank EPSRC (UK) for a DTA studentship (Grant No. EP/L505079/1) and the EPSRC UK National Mass Spectrometry Facility at Swansea University
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Publikationsverlauf

Received: 30. April 2017

Accepted after revision: 12. Juni 2017

Publikationsdatum:
18. Juli 2017 (online)


Published as part of the ISHC Conference Special Section

Abstract

Treatment of ortho-benzyloxyphenyloxazolines with butyllithium and potassium tert-butoxide results in cyclisation with ring opening of the oxazoline to give 2-aryl-3-aminobenzofurans. The reaction also occurs with the corresponding benzylthio and benzylamino compounds to give benzothiophenes and indoles, respectively. Use of an ortho-allyloxyphenyloxazoline gives the corresponding 2-vinylbenzofuran, while both α-methylbenzyloxy and benzylsulfonyl compounds form stable spirooxazolidine products. The X-ray structure of an aminobenzothiophene product has been determined.

Supporting Information

 
  • References and Notes

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