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