Preparation of Quaternary Centers via Nickel-Catalyzed Suzuki–Miyaura Cross-Coupling of Tertiary Sulfones

We describe the development of a nickel-catalyzed Suzuki–Miyaura cross-coupling of tertiary benzylic and allylic sulfones with arylboroxines. A variety of tertiary sulfones, which can easily be prepared via a deprotonation–alkylation route, were reacted to afford symmetric and unsymmetric quaternary products in good yields. We highlight the use of either BrettPhos or Doyle’s phosphines as effective ligands for these challenging desulfonative coupling reactions. The utility of this methodology was demonstrated in the concise synthesis of a vitamin D receptor modulator analogue

Enantiospecific Cross-coupling of Cyclic Alkyl Sulfones

Methods to form carbon-carbon bonds efficiently and with control of stereochemistry are critical for the construction of complex molecules. Cross-coupling reactions are among the most efficient and widely used reactions to construct molecules, with reactions enabling the retention or installation of chirality as recent additions to this powerful toolbox. Sulfones are robust, accessible organic electrophiles that have many attractive features as cross-coupling partners, however since the first example of their use in 1979, there have been no examples of their use in enantio-selective, -specific or -convergent cross-couplings. The high acidity of sulfones makes it unclear whether this transformation is even possible outside tertiary systems. Herein we report the enantiospecific cross-coupling of cyclic sulfones and Grignard reagents. Up to 99% chirality transfer is observed despite the strong basicity of the Grignard components. In situ monitoring reveals that the cross-coupling is kinetically competitive with competing deprotonation, resulting in a highly enantioselective transformation

Arylative Desulfonation of Diarylmethyl Phenyl Sulfone with Arenes Catalyzed by Scandium Triflate

A scandium-triflate-catalyzed arylative desulfonation of diarylmethyl phenyl sulfones with arenes and heteroarenes was established. A variety of both sulfone and arene substrates were reacted to afford symmetric and nonsymmetric triarylmethanes in good yields. Further transformations of the resulting triarylmethanes and application to the concise synthesis of a bactericidal agent analogue were also demonstrated