Synthesis 2018; 50(24): 4875-4882
DOI: 10.1055/s-0037-1610240
paper
© Georg Thieme Verlag Stuttgart · New York

Large-Scale Flow Photochemical Synthesis of Functionalized trans-Cyclooctenes Using Sulfonated Silica Gel

Ampofo Darko*
a   Department of Chemistry, University of Tennessee, Knoxville, TN, 37996, USA
,
Samantha J. Boyd
b   Department of Chemistry and Biochemistry, University of Delaware, Newark DE 19716, USA   Email: jmfox@udel.edu
,
Joseph M. Fox*
b   Department of Chemistry and Biochemistry, University of Delaware, Newark DE 19716, USA   Email: jmfox@udel.edu
› Author Affiliations
This work was supported by NIH R01EB014354, R01DC014461, and NSF DMR-1506613. Spectra were obtained with instrumentation supported by NIH grants P20GM104316, P30GM110758, S10RR026962, S10OD016267 and NSF grants CHE-0840401, CHE-1229234, and CHE-1048367.
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Publication History

Received: 19 July 2018

Accepted after revision: 20 July 2018

Publication Date:
20 August 2018 (online)


‡ These authors contributed equally

Abstract

Functionalized trans-cyclooctenes are useful bioorthogonal reagents that are typically prepared using a flow photoisomerization method in which the product is captured by AgNO3 on silica gel. While this method is effective, the leaching of silver can be problematic when scaling up syntheses. It is shown here that Ag(I) immobilized on tosic silica gel can be used to capture trans-cyclooctene products at higher loadings without leaching. It is demonstrated that the sulfonated silica gel can be regenerated and reused with similar yields over multiple runs. Nine different trans-cyclooctenes were synthesized, including those commonly utilized in bioorthogonal chemistry as well as new amine and carboxylic acid derivatives.

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