Alkenes coupling with heteroaromatic

Oxidative cross-coupling with alkenes is possible with Pd(OAc)2 [109], The reaction proceeds by the palladation of benzene to form phenylpalladium acetate (164), followed by alkene insertion and elimination of /1-hydrogen. Heteroaromatics such as furan and thiophene react more easily than benzene [109]. Stilbene (177) is formed by the reaction of benzene and styrene. The complex skeleton of paraberquamide 179 was obtained in 80% yield by the Pd(II)-promoted coupling of the indole ring with the double bond in 178, followed by reduction of the intermediate with NaBELt [110]. 

Water-soluble palladium(O) complexes have also been used as homogeneous catalysts in aqueous-solution alkylation reactions. The particular complex that has been used is Pd(TPPMS>3. Aryl or heteroaromatic halides can be coupled with aryl or vinyl boronic acids, alkynes, alkenes, or dialkyl phosphites with this palladium(0) complex. This complex in aqueous solution can also be used for the coupling of alkynes with unprotected iodonucleotides, iodonucleosides, and iodoamino acids (133). 

The CDC reaction of arenes and alkenes can be applied to heteroaromatic compounds. Coupling with furan, thiophene, pyrrole, benzofuran. 

On the other hand, the direct arylation of carbanionic species generated from substrates having relatively acidic hydrogens such as active methylene compounds and ketones can occur (mechanism B) [5,6]. Aryl halides are also capable of coupling directly with appropriately functionalized aromatic substrates and five-membered heteroaromatic compounds as formal carbon nucleophiles via cleavage of their unactivated C-H bonds [5,7-9]. The Fujiwra-Moritani reaction, which is the arylation of alkenes with arenes, is also useful for preparing arylalkenes without employing any halides (mechanism D) [10,11]. 

Satoh, M. Miyaura, N. Suzuki, A. 1987. Palladium catalyzed cross-coupling reaction of (1-ethoxy-l-alken-2-yl)boranes with ortho-functionalized iodoarenes. A novel and convenient synthesis of benzo fused heteroaromatic compounds. Synthesis 373-377. 

Heteroaromatic compounds show similar behavior to benzene derivatives. Furan, pyrrole, thiophene, benzofuran, indole, benzothiophene, and their related compounds undergo CDC reactions with alkenes. In the case of furan, the coupling reactions with acrylates, acrylonitrile, styrenes, and... 

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