Rapid Construction of Multisubstituted Olefin Structures Using Vinylboronate Ester Platform Leading to Highly Fluorescent Materials

Abstract

[reaction: see text] A catalytic one-pot triarylation on the C=C core of vinylboronate pinacol ester (1) produces extended pi-systems based on a multisubstituted olefin structure very rapidly. We established an efficient protocol for the Pd-catalyzed double C-H arylation of 1 with aryl halides, which was successfully integrated with C-B arylation with aryl halides (cross-coupling) in one pot. By using this method, several highly fluorescent materials with a wide range of color variations (blue to red) were discovered.

Multisubstituted Olefins: Platform Synthesis and Applications to Materials Science and Pharmaceutical Chemistry

“…25). 25 0:06). Along with the discovery of highly fluorescent materials, the rationalization of properties is also important in materials science, although not necessarily easy.…”

“…It was found that the emission color as well as fluorescence quantum yields depended significantly on the attaching sites and the nature of the aryl groups attached. 18,23,25 Discovery of Efficient Blue-Emitter and Rapid Structure-Property Relationship Analysis. Our synthetic strategy described in Fig.…”

“…17 can easily be applied to the preparation of derivatives of DPVBi 14a, 34 which has been used as a blue-emitter in organic electroluminescence devices. 18,25 Fortunately, our library-based approach within this class of -system led to the discovery of the strong blue-emitting material 14d (Fig. 25).…”

“…11). 25 Moreover, we found that by simply adding aryl halides, NaOH, and H 2 O to the reaction mixture of the double Mizoroki-Heck reaction, triarylethenes 6 could be obtained in good overall yields (Fig. 11).…”

“…11. 25 In our multisubstituted olefin synthesis using vinylsilane or vinylboronate as a platform, substituents such as aryl, heteroaryl, and alkenyl groups are efficiently introduced, due mainly to the high reactivity of organic halides bearing those groups in metal-catalyzed coupling reactions. 5,7 However, the utility of our strategy would be substantially enhanced if we could extend the scope of introducible organic groups.…”