Understanding Site Selectivity in the Palladium-Catalyzed Cross-Coupling of Allenylsilanolates

Published as part of the Cluster Silicon in Synthesis and Catalysis

Abstract

Allenylsilanolates can undergo cross-coupling at the α- or γ-terminus, and site selectivity appears to be determined by the intrinsic transmetalation mechanism. Fine-tuning of concentration, nucleophilicity, and steric bulk of the silanolate moiety allows for the selective formation of one isomer over the other. Whereas the α-isomer can be obtained in synthetically useful yield, the γ-isomer is favored only when employing reaction conditions that are inevitably associated with diminished reactivity.

Key words

allenes - cross-coupling - organosilanes - palladium - site selectivity - transmetalation

• References and Notes

• 1 Current address: Gilead Sciences, Inc., Foster City, CA 94404, USA.
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