1323722-87-7Relevant academic research and scientific papers
Chiral N-Heterocyclic Carbene Ligands Bearing a Pyridine Moiety for the Copper-Catalyzed Alkylation of N-Sulfonylimines with Dialkylzinc Reagents
Soeta, Takahiro,Ishizaka, Tomohiro,Tabatake, Yuta,Ukaji, Yutaka
, p. 16773 - 16778 (2014)
Amino acid-derived chiral imidazolium salts, each bearing a pyridine ring, were developed as N-heterocyclic carbene ligands. The copper-catalyzed asymmetric alkylation of various N-sulfonylimines with dialkylzinc reagents in the presence of these chiral imidazolium salts afforded the corresponding alkylated products with high enantioselectivity (up to 99 % ee). The addition of HMPA to the reaction mixture as a co-solvent is critical in terms of chemical yield and enantioselectivity. A wide range of N-sulfonylimines and dialkylzinc reagents were found to be applicable to this reaction. Amino acid-derived chiral imidazolium salts, each bearing a pyridine ring, were developed as N-heterocyclic carbene ligands. The copper-catalyzed asymmetric alkylation of various N-sulfonylimines with dialkylzinc reagents in the presence of these chiral imidazolium salts afforded the corresponding alkylated products with high enantioselectivity (up to 99 % ee; see scheme). A wide range of N-sulfonylimines and dialkylzinc reagents were found to be applicable to this reaction.
Highly enantioselective arylation of N -tosylalkylaldimines catalyzed by rhodium-diene complexes
Cui, Zhe,Yu, Hong-Jie,Yang, Rui-Feng,Gao, Wen-Yun,Feng, Chen-Guo,Lin, Guo-Qiang
, p. 12394 - 12397 (2011/10/02)
A highly enantioselective rhodium-catalyzed arylation of aliphatic N-tosylaldimines has been developed. The combination of chiral bicyclo[3.3.0]octadiene ligands, an active rhodium hydroxide complex, and neutral reaction conditions is the key to achieving high yield and enantioselectivity. The application of this method is demonstrated by the enantioselective synthesis of chiral 2-aryl pyrrolidines and piperidines in a one-pot procedure. Furthermore, excellent results are also obtained for the imine substrates with the more readily cleavable N-nosyl protecting group.
