Synthesis 2009(11): 1791-1796  
DOI: 10.1055/s-0028-1088066
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Efficient and Recyclable Phthalocyanine-Based Sensitizers for Photo­oxygenation Reactions

Hu Xu, Wing-Kin Chan, Dennis K. P. Ng*
Department of Chemistry and Center of Novel Functional Molecules, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, P. R. of China
Fax: +852(2603)5057; e-Mail: dkpn@cuhk.edu.hk;
Further Information

Publication History

Received 6 January 2009
Publication Date:
27 April 2009 (online)

Abstract

Treatment of 4,5-bis(4-methoxycarbonylphen­oxy)phthalonitrile with Zn(OAc)2˙2H2O and 1,8-diazabicyclo[5.4.0]undec-7-ene in octan-1-ol or dodecan-1-ol led to base-promoted cyclotetramerization. Under these conditions, transesterification also occurred to give the corresponding zinc(II) octakis(4-alkoxycarbonylphenoxyphthalocyanines. These two macrocycles, together with another two pegylated silicon(IV) phthalocyanines, were found to be highly efficient sensitizers for the photooxygenation of a series of alkenes and 1-naphthol. In general, the zinc(II) analogues exhibit a higher photostability and can be recycled at least four times without a significant loss of activity.

1

Present address: Department of Chemistry and Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. of China.