Tertiary and Quaternary Carbon Formation via Gallium-Catalyzed Nucleophilic Addition of Organoboronates to Cyclopropanes Truong N. Nguyen Jeremy A. May 10.1021/acs.orglett.7b03349.s001 https://acs.figshare.com/articles/journal_contribution/Tertiary_and_Quaternary_Carbon_Formation_via_Gallium-Catalyzed_Nucleophilic_Addition_of_Organoboronates_to_Cyclopropanes/5702569 GaCl<sub>3</sub> and (IPr)­GaCl<sub>3</sub>/AgSbF<sub>6</sub> formed γ-tertiary and γ-quaternary carbons via homoconjugate addition of organoboron nucleophiles to diester- and ketone-functionalized cyclopropanes. Electron donor group cyclopropane substituents were not needed, allowing electron-deficient aryl, alkenyl, alkyl, and hydrogen-substituted cyclopropanes to be used. The catalytic conditions were compatible with alkenyl, alkynyl, and aryl nucleophiles, including ortho-substituted aromatics, to synthesize highly hindered quaternary carbons. Alkynyl nucleophiles formed substituted cyclopentenes. A control experiment supports an intermediate carbocation in quaternary carbon center formation. 2017-12-14 15:44:27 aryl nucleophiles quaternary carbon center formation organoboron nucleophiles ortho-substituted aromatics quaternary carbons hydrogen-substituted cyclopropanes homoconjugate addition Alkynyl nucleophiles electron donor group cyclopropane substituents control experiment ketone-functionalized cyclopropanes alkenyl γ- quaternary carbons Quaternary Carbon Formation electron-deficient aryl Gallium-Catalyzed Nucleophilic Addition Cyclopropanes GaCl 3