249922-28-9Relevant academic research and scientific papers
Enantioselective Intermolecular C-H Amination Directed by a Chiral Cation
Fanourakis, Alexander,Paterson, Kieran J.,Phipps, Robert J.,Williams, Benjamin D.
supporting information, p. 10070 - 10076 (2021/07/21)
The enantioselective amination of C(sp3)-H bonds is a powerful synthetic transformation yet highly challenging to achieve in an intermolecular sense. We have developed a family of anionic variants of the best-in-class catalyst for Rh-catalyzed C-H amination, Rh2(esp)2, with which we have associated chiral cations derived from quaternized cinchona alkaloids. These ion-paired catalysts enable high levels of enantioselectivity to be achieved in the benzylic C-H amination of substrates bearing pendant hydroxyl groups. Additionally, the quinoline of the chiral cation appears to engage in axial ligation to the rhodium complex, providing improved yields of product versus Rh2(esp)2 and highlighting the dual role that the cation is playing. These results underline the potential of using chiral cations to control enantioselectivity in challenging transition-metal-catalyzed transformations.
CHEMICAL COMPOUNDS
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Page/Page column 91, (2008/06/13)
The invention provides compounds formula I, their preparation, and their use as pharmaceutically active immunosuppressive agents for the treatment of autoimmune disorders, organ transplant rejection, disorders associated with an activated immune system, a
Cyclization of benzyne-tethered alkyllithiums: Preparation of 3-substituted benzocyclobutenes and 5-substituted tetralins
Bailey, William F.,Longstaff, Sarah C.
, p. 6899 - 6901 (2007/10/03)
A five-step, one-pot preparation of isomerically pure 3-substituted benzocyclobutenes or 5-substituted tetralins in 20-40% yield from the appropriate α-(2-fluorophenyl)-ω-iodoalkane, involving generation and subsequent 4-or 6-exo cyclization of a benzyne-tethered alkyllithium, is described.
