C-H bond activation has been established as an attractive strategy to access axially chiral biaryls, and the most straightforward method is direct C-H arylation of arenes. However, the arylating source has been limited to several classes of reactive and bulky reagents. Reported herein is rhodium-catalyzed 1:2 coupling of diarylphosphinic amides and diarylacetylenes for enantio- and diastereoselective construction of biaryls with both central and axial chirality. This twofold C-H activation reaction stays contrast to the previously explored Miura-Satoh type 1:2 coupling of arenes and alkynes in terms of chemoselectivity and proceeded under mild conditions with the alkyne acting as a rare arylating reagent. Both C-H activation events are stereo-determining and are under catalyst control, with the 2nd C-H activation being diastereo-determining in a remote fashion. Analysis of the stereochemistries of the major and side products suggests moderated enantioselectivity of the initial C-H activation-desymmetrization process. However, the minor stereoisomeric (R) intermediate is consumed more readily in undesired protonolysis, eventually resulting in high enantio- and diastereoselectivity of the major product.
Panjie Hu Shaanxi Normal University (SNNU)
download asset manuscript.pdf 0.64 MB [opens in a new tab] cloud_download
pdf : 0.64 MB
download asset SI.pdf 4 MB [opens in a new tab] cloud_download
pdf : 4 MB