Heck Reaction of Electronically Diverse Tertiary Alkyl Halides.

The efficient Pd-catalyzed Heck reaction of diverse tertiary alkyl halides with alkenes has been developed. Unactivated tertiary alkyl halides efficiently react at room temperature under visible light irradiation with no exogenous photosensitizers required. For activated tertiary alkyl halides, the same catalytic system works well without light. These methods offer a general access to electronically diverse alkenes possessing quaternary and functionalized tertiary allylic carbon centers. The substituents at these centers include alkyl-, carbalkoxy-, tosyl-, phosphonyl-, and boronate groups. It was also shown that the end-game mechanism of this transformation may vary depending on the type of the substrates used.