Document Type

Article

Publication Date

4-2011

Publication Title

Synlett

Volume

2011

Issue

6

First Page

805

Last Page

808

DOI

10.1055/s-0030-1259718

Keywords

alkynes, cobalt, cyclization, carbocycles, regioselectivity

Abstract

The CpCo(CO)2-catalyzed cocyclization of 1,2-diethynyl- 4-methoxybenzene with alkynes can be applied to the synthesis of ‘spacer’-naproxen [2-(6-methoxybiphenylen-2-yl)propanoic acid] and its 7-methoxy isomer, ‘spacer’-isonaproxen. While unsymmetrical alkynes are incorporated without regioselectivity, the methoxy group in 6-methoxy-2,3-bis(trimethylsilyl)biphenylene directs electrophiles to C-3, thus allowing for regiochemical differentiation between the 2- and 3-positions.

Funding Reference Number

NSF (CHE-0907800)

Comments

First published in Synlett, copyright © Georg Thieme Verlag, an imprint of Thieme Publishing. To access the final version, see DOI: 10.1055/s-0030-1259718 at https://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-0030-1259718.

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