Resveratrol, Heck reaction

This protocol could be extended to a range of different ,/i-unsaturated carbonyl compounds and either activated or deactivated aryl iodides [22], An application of related Heck chemistry to the synthesis of methylated resveratrol (3,4, 5-trihydroxy-( )-stilbene) is shown in Scheme 6.4 [23]. The phytoalexin resveratrol exhibits a variety of interesting biological and therapeutic properties, among them activity against several human cancer cell lines. Botella and Najera have shown that the trimethyl ether of resveratrol (Scheme 6.4) can be rapidly prepared by microwave-assisted Heck reaction of the appropriate aryl iodide and styrene derivatives, using the same oxime-derived palladacycle as indicated in Scheme 6.3. 

Scheme 9 Decarbonylative Heck reaction in the synthesis of resveratrol...

Novel resveratrol derivatives (polyhydroxylated (E)-stilbenes), synthesized by Mizoroki-Heck reactions, revealed potent butyrylcholinesterase-inhibiting properties [225]. 

BoteUa, L. and Najera, C. (2004) Synthesis of methylated resveratrol and analogues by Heck reactions in organic and aqueous solvents. Tetrahedron, 60, 5563-70. 

Moreover, several resveratrol-derived natural products can be synthesized by a palladium-catalyzed cascade reaction of bromostilbene derivative 121 and tolane 122 (Scheme 60) (110). In this cascade reaction, intermolecular Heck reaction proceeds first, followed by intramolecular Heck cyclization to give the desired carbon framework of dimeric resveratrol natural products. 

Using 8 X 10 molar equivalents of PdAS-V, coupled products were obtained in yields up to 92% and the catalyst was recycled five times without apparent loss of activity. Ikegami et al. demonstrated the practical application of this catalyst by using the PdAS-V-promoted Heck reaction to prepare resveratrol, a naturally occurring phytoalexin in plants which has potential anticancer properties. ... 

The Fujiwara-Moritani reaction enables the coupling of alkenes with arenes under oxidative conditions—also named oxidative Heck reaction (for the mechanism, see Ref [ 29]) Garcia-Rubia et al. used this Pd"-catalyzed oxidative direct C-H alkenylation to produce /rans-stilbene derivatives.As exemplified by their synthesis of pterostilene (Scheme 5-45), a partially methylated resveratrol derivative, a 2-pyridyl sulfinyl group efficiently promotes the Pd"-catalyzed ortho C-H olefination of arenes and can be readily removed or transformed into a thiol group. 

Andrus and Liu exploited a Pd(NHC) decarbonylative Heck coupling reaction in the total synthesis of resveratrol [59], The catalyst was formed in situ with Pd(OAc), and IPr HCl. 

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