Chiral Phosphoric Acid Catalyzed Transfer Hydrogenation: Facile Synthetic Access to Highly Optically Active Trifluoromethylated Amines

Alkyl Transfer from CC Cleavage

“…Benzothiazole was another type of biologically inspired hydrogen-transfer donor that had been used successfully for the hydrogenation of imines. [18] Therefore, we hoped that our alkyl-transfer reaction would also take place with benzothiazole substrates. As we had imagined, the designed alkyl transfer proceeded smoothly in the synthesis of amines with high yield (Scheme 4, products 3 a and 4 c).…”

Chiral Phosphoric‐Acid‐Catalyzed Transfer Hydrogenation of Ethyl Ketimine Derivatives by Using Benzothiazoline

“…The substituent effect of benzothiazoline was confirmed in many examples of the transfer hydrogenation of CN bonds catalyzed by chiral phosphoric acid 6b–j. Although we have recently reported that there are some differences in reactivity and enantioselectivity in transfer hydrogenation of trifluoromethylated ketimines by using those two hydrogen donors, the mechanistic insights and stereochemical outcome were not discussed 6c. j Hantzsch ester and benzothiazoline have large structural differences (Figure 1).…”

Gmelin‐Beilstein‐Denkmünze: Engelbert Zass / Nagoya‐Medaille für organische Chemie: P. Knochel, T. Akiyama und M. Terada / IKCOC‐Preis: M. T. Reetz

“…1994 ging er an die Gakushuin University, an der er nun ordentlicher Professor ist. In seiner Forschung beschäftigt er sich mit asymmetrischen Reaktionen, die durch chirale Brønsted‐Säuren katalysiert werden, metallkatalysierten Umsetzungen und der Aktivierung von C‐F‐Bindungen 3. In der Angewandten Chemie erschien zuletzt eine Arbeit von ihm über eine Transferhydrierung, die durch eine chirale Phosphorsäure katalysiert wird…”