Publications by authors named "Kaiming Han"
Article Synopsis
- The study focuses on the unique properties of sulfenamides and explores a selective method for creating N-arylated sulfenamides through a Chan-Lam coupling.
- A specialized pybox ligand plays a crucial role in ensuring that the reaction favors the formation of C-N bonds over C-S bonds by preventing the sulfenamides from binding too tightly to the copper catalyst.
- Experimental techniques like UV-Vis and EPR are used to confirm the reaction intermediates, while computational studies indicate that the reaction is favored both kinetically and thermodynamically.
Herein, an unprecedented synthetic route to sulfilimines via a copper-catalyzed Chan-Lam-type coupling of sulfenamides is presented. A key to success in this novel transformation is the chemoselective -arylation of S(II) sulfenamides to form S(IV) sulfilimines, overriding the competitive, and more thermodynamically favored, C-N bond formation that does not require a change in the sulfur oxidation state. Computations reveal that the selectivity arises from a selective transmetallation event where bidentate sulfenamide coordination through the sulfur and oxygen atoms favors the -arylation pathway.
View Article and Find Full Text PDFA novel palladium-catalyzed aryl-furanylation of alkenes is described. This protocol provided a straightforward route to the synthesis of various benzofuran-containing 3,3-disubstitutedoxindole derivatives bearing a quarternary carbon center. In the cascade process, one C(sp)-O bond, two C(sp)-C(sp) bonds, an oxindole, and a furan ring are formed in a single chemical operation.
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