Transmetalation as a Route to Novel Styryllithium Reagents

Abstract

[structure: see text] Transmetalation of beta-tributyl(styryl)stannanes with n-BuLi gives the functional equivalents of the corresponding styryllithium intermediates. Reaction of the intermediates with chlorotrimethylsilane, iodomethane, or dimethyl sulfate gives the substituted styryl products in moderate to good yields. In all cases, the configuration about the double bond was retained in the products.

Carbanion generation through tin-lithium exchange of vinyl-, aryl-, and hetarylstannanes

“…31 More recently, the same reagent was prepared by transmetallation of (E)-β-tributyl(styryl)stannane with BuLi (Equation 14). 32 The (Z)-isomer was also transmetallated successfully, which was in contrast to the earlier report. The meta-and para-dilithiated reagents were also prepared successfully (Equation 15), as was the 1,3,5-trilithiated reagent (Equation 16).…”

“…The meta-and para-dilithiated reagents were also prepared successfully (Equation 15), as was the 1,3,5-trilithiated reagent (Equation 16). 32 In all cases, configuration about the double bond was retained. It is possible that in reactions with electrophiles, tin-lithium exchange in these reactions occurred in a stepwise fashion, rather than through the dianionic or trianionic species.…”

Organodilithium Intermediates as Useful Dianionic Synthons: Recent Advances

“…The starting tri-nbutyl(styryl)stannanes 224-226 can be easily prepared by hydrostannation of the corresponding ethynylbenzenes. The reaction of polylithiated intermediates 227-229 with chlorotrimethylsilane or iodomethane gave the substituted styryl products 230-232 in moderate to good yields, the configuration of the double bond being retained in the final products (Scheme 52) [111].…”

Cyclocarbopalladation: Sequential Cyclization and C—H Activation/Stille Cross‐Coupling in the Pd‐5‐exo‐dig Reaction.

“…13 C NMR spectra were recorded at 50 of 75 MHz at ambient temperature in Stannanes derivatives 6, 13-16, 33 are commercially available; and 7-12, 34, 38 were prepared by litterature methods. 3,4,5…”