13685-27-3Relevant academic research and scientific papers
Twofold C?H Activation-Based Enantio- and Diastereoselective C?H Arylation Using Diarylacetylenes as Rare Arylating Reagents
Hu, Panjie,Kong, Lingheng,Li, Xingwei,Wang, Fen,Zhu, Xiaolin
, p. 20424 - 20429 (2021)
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 stereochemistry of the major and side products suggests moderate enantioselectivity of the initial C?H activation–desymmetrization process. However, the minor (R) rhodium vinyl intermediate is consumed more readily in undesired protonolysis, eventually resulting in high enantio- and diastereoselectivity of the major product.
