Accessing α-Arylated Nitriles via BF3·OEt2 Catalyzed Cyanation of para-Quinone Methides Using tert-Butyl Isocyanide as a Cyanide Source.

BF3·OEt2 catalyzed 1,6-conjugate addition of tert-butyl isocyanide to para-quinone methides and fuchsones for the synthesis of α-diaryl and α-triaryl nitriles has been reported. This protocol allows α-diaryl- and α-triaryl nitriles to be accessed in good to excellent yields and with a broad substrate scope, which could be further functionalized to give a versatile set of products. This is the first example wherein tert-butyl isocyanide has been used as a cyanide source for the 1,6-conjugate addition.