Pentafluorophenyl Transfer:  A New Group-Transfer Reaction in Organoborate Salts

Irradiation of isoquinolinium hydroxytris(pentafluorophenyl)borate,<b> 1</b>, and phenanthridium hydroxytris(pentafluorophenyl)borate,<b> 2</b>, in either CH<sub>2</sub>Cl<sub>2</sub> or CH<sub>3</sub>CN resulted in C<sub>6</sub>F<sub>5</sub> transfer to the isoquinolinium and phenanthridium cations, generating 2-methyl-1-(2,3,4,5,6- pentafluorophenyl)-1,2-dihydroisoquinoline, <b>3</b>, and 2-methyl-1-(2,3,4,5,6-pentafluorophenyl)-1,2-dihydrophenanthridine, <b>4</b>, respectively. In addition, photogeneration of H<sub>2</sub>O·B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub> resulted from <b>1</b>. Photogeneration of C<sub>6</sub>F<sub>5</sub>−C<sub>6</sub>F<sub>4</sub>H from HO−B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub><sup>-</sup> and of C<sub>6</sub>H<sub>5</sub>−C<sub>6</sub>F<sub>4</sub>H from C<sub>6</sub>H<sub>5</sub>−B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub><sup>-</sup> was discovered.