Synthesis 2015; 47(03): 421-428
DOI: 10.1055/s-0034-1379369
paper
© Georg Thieme Verlag Stuttgart · New York

Asymmetric N-Heterocyclic Carbene Catalyzed Annulation of 2-Alkenylbenzothiazoles with α-Chloro Aldehydes

Xiaoxiao Song
Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany   Fax: +49(241)8092127   Email: enders@rwth-aachen.de
,
Qijian Ni
Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany   Fax: +49(241)8092127   Email: enders@rwth-aachen.de
,
Chen Zhu
Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany   Fax: +49(241)8092127   Email: enders@rwth-aachen.de
,
Gerhard Raabe
Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany   Fax: +49(241)8092127   Email: enders@rwth-aachen.de
,
Dieter Enders*
Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany   Fax: +49(241)8092127   Email: enders@rwth-aachen.de
› Author Affiliations
Further Information

Publication History

Received: 26 September 2014

Accepted after revision: 30 September 2014

Publication Date:
06 November 2014 (online)


Dedicated to Professor Martin Jansen on the occasion of his 70th birthday

Abstract

Diastereo- and enantioselective N-heterocyclic carbene catalyzed 1-azadiene Diels–Alder reactions of (E)-2-styrylbenzothiazoles with α-chloro aldehydes are reported. This annulation strategy provides an efficient access to medicinally important dihydrobenzothiazolopyridin-1-ones in good to excellent yields (44–97%) with very good to excellent stereoselectivities (up to 9:1 dr, 98% ee) and tolerates quite a range of substituents.

Supporting Information