Unusual Intramolecular Hydrogen Transfer in 3,5-Di(triphenylethylenyl) BODIPY Synthesis and 1,2-Migratory Shift in Subsequent Scholl Type Reaction

Ming Hui Chua; Kuo-Wei Huang; Jianwei Xu; Jishan Wu

doi:10.1021/acs.orglett.5b01916

Unusual Intramolecular Hydrogen Transfer in 3,5-Di(triphenylethylenyl) BODIPY Synthesis and 1,2-Migratory Shift in Subsequent Scholl Type Reaction

Org Lett. 2015 Sep 4;17(17):4168-71. doi: 10.1021/acs.orglett.5b01916. Epub 2015 Aug 17.

Authors

Ming Hui Chua^{1

2}, Kuo-Wei Huang³, Jianwei Xu¹, Jishan Wu^{1

2}

Affiliations

¹ Institute of Materials Research and Engineering, A*STAR , 3 Research Link, Singapore, 117602, Singapore.
² Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore, 117543, Singapore.
³ Division of Physical and Life Sciences and Engineering and KAUST Catalysis Center, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900, Saudi Arabia.

PMID: 26280104
DOI: 10.1021/acs.orglett.5b01916

Abstract

The straightforward synthesis of 3,5-di(triphenylethylenyl) BODIPYs 1-3 from the condensation of 2-(triphenylethylenyl) pyrrole with aryl aldehydes are surprisingly found to produce side products that are hydrogenated at one of the two triphenylethylene substituents. It was also observed that the subsequent Scholl type reaction of 1 resulted in a "1,2-migratory shift" of one triphenylethylene substituent in addition to a ring closing reaction. Preliminary investigations, including DFT calculations and isolation of intermediates, were conducted to study these unusual observations on BODIPY chemistry.