13031-10-2Relevant academic research and scientific papers
Palladium-catalyzed asymmetric hydrogenation of simple ketones activated by Br?nsted acids
Zhou, Xiao-Yu,Wang, Duo-Sheng,Bao, Ming,Zhou, Yong-Gui
supporting information; experimental part, p. 2826 - 2829 (2011/06/21)
Homogeneous Pd(OCOCF3)2/(R)-C4-TunePhos has been successfully applied in the asymmetric hydrogenation of simple ketones activated by catalytic amount of Br?nsted acid with up to 88% ee.
Enantioselective alkenylation and phenylation catalyzed by a chiral CuF complex
Tomita, Daisuke,Wada, Reiko,Kanai, Motomu,Shibasaki, Masakatsu
, p. 4138 - 4139 (2007/10/03)
A new method for CuF-catalyzed alkenylation and phenylation of aldehydes and an activated ketone using air- and moisture-stable alkenylsilanes and phenylsilane as a nucleophile is described. This methodology was extended to highly enantioselective catalytic alkenylation and phenylation using DTBM-SEGPHOS as a chiral ligand. Substrate generality is broad, and an alkenylsilane with a long alkyl chain and an internal alkenylsilane can be also used as a nucleophile. The key to success partly involves the accelerated regeneration of reactive alkenylcopper and phenylcopper through transmetalation from the silylated nucleophiles, and stabilization of the reactive copper reagents, both of which are effected by the diphosphine ligands. Copyright
Stereoisomerization of Ketene Imines
Lambrecht, Johanna,Gambke, Brigitte,Seyerl, Joachim von,Huttner, Gottfried,Kollmannsberger-von Nell, Georg,et al.
, p. 3751 - 3771 (2007/10/02)
Barriers to racemization in solution of the ketene imines 1a - y and X-ray structures of the ketene imines 1s and z are described.Similar to allenes all ketene imines have dihedral angles of 90 deg between the C- and N-substituents.The barriers to racemization range from 30 to 63 kJmol-1 and are lowered by electron attracting substituents on C and N.The barriers of m- and p-substituted N-arylketene imines give a linear Hammett correlation with ?- constants.N-Arylketene imines racemize through inversion at nitrogen and simultaneous rotation of the aryl group around the N - aryl bond.
