Heck Reaction of Electronically Diverse Tertiary Alkyl Halides

Abstract

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.

Palladium‐Catalyzed Decarboxylative Heck‐Type Coupling of Activated Aliphatic Carboxylic Acids Enabled by Visible Light

“…The ( E )‐substitution pattern was additionally verified by crystal structures of compounds 3 ca and 3 fk . For analogous reactions with organic alkyl halides, especially with primary halides, the formation of a small amount of the ( Z )‐isomer was observed –…”

Catalysis with Palladium Complexes Photoexcited by Visible Light

“…[22] Ther eaction of a-heteroatom-substituted methyl iodides and bromides with vinyl arenes proceeded smoothly,t hereby generating diverse functionalized allylic systems in good yields (39 a-39 m, 39 q). [23] Interestingly,l ight was not necessary for the reaction of activated tertiary alkyl halides [40!41;Eq. Later,t he same group applied their photoinduced conditions to the efficient Heck reaction of activated and unactivated tertiary alkyl iodides with styrene derivatives (39 r-39 z, 39 ab, 39 ac)a nd acrylonitrile (39 aa).…”

Pd Supported IRMOF-3: Heterogeneous, Efficient and Reusable Catalyst for Heck Reaction

“…One of the fundamental transformations in organic chemistry is the Heck reaction used for reacting substituted halobenzenes and vinyl halides with olefins (Scheme 1). In general, the reaction of alkyl halides with olefins is not satisfactory, because of a premature β-hydrogen elimination and slow oxidative addition rates [24]. Challenges to enhance the scope of enantioselective Heck reactions have been very recently well documented [25].…”