Coupling reactions Allyltrimethylsilane

Allyltriphenylstannane has been employed successfully in cross-couplings with a variety of terminal olefins containing (inter alia) ketal, ester, and cyano groups [121]. Only the MoF6 catalyst appeared to work at a reasonable rate in most cases. Both E and Z products were formed in yields that varied from 50% to 80%. Several substrates underwent smooth cross-coupling with allyltrimethylsilane under comparable reaction conditions. 

The coupling reaction of (/ ,Z)-4-(difluorophenylsilyl)-2-hexene (69% ee) [33] with 2-naphthyl triflate in the presence of Pd(PPh3)4 as the catalyst and TASF in DMF afforded (5, )-2-(2-naphthyl)-3-hexene of 63% ee [Eq.(32)]. Thus, the stereochemistry was proved to be anti with y-regioselectivity (see Section 10.7.1). These results are consistent with the Se reaction of allyltrimethylsilanes. When TASF was replaced by CsF, the stereochemical outcome was again anti, but the CsF-mediated reaction in THF gave 5yn-coupled product. 

Displacement reactions. 1,3-Dibromo-l-trimethylsilylpropene is available from allyltrimethylsilane by reaction with NBS. The dibromo compound couples with Grignard reagents to effect chain elongation. With further displacement of the vinylic bromine and protodesilyation, it constitutes an intriguing approach to (Z)-alkenes. ... 

Smith and coworkers next extended Type II ARC domino protocol beyond dithiane arena by designing a variety of effective ARC linchpins with different ASGs capable of three and four component couplings. In their first effort toward this goal, they developed readily available 2-bromoallylsilane [62a], and subsequently, allyltrimethylsilane 185 [63], and recently o-TMS (trimethylsilyl) benzaldehyde 188 as promising linchpins for Type II ARC process [64, 65]. However, domino anionic relay reactions with these linchpins 185 and 188 are not discussed in this chapter, since they are not initiated by nucleophilic substitution as the first step. 

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