59320-63-7Relevant articles and documents
Selective Hydrogen Transfer in N-(Diphenylmethyl)-1-phenylethan-1-imine
Li, J.,Shi, Y. B.,Xing, J. D.
, p. 589 - 597 (2021/06/02)
Abstract: Proton transfer processes mediate many organic reactions. How to realizestereochemical control of this process has always been a challenging topic inthe field of asymmetric catalysis. In this study, N-(diphenyl-methyl)-1-phenylethan-1-imine (Schiff base derivedfrom 2,2-diphenylethan-1-amine and acetophenone) was used as substrate, anddifferent near neutral solvents and various chiral metal complex catalysts wereused to carry out photoinduced C=N double bond transfer in the substrate underirradiation with a mercury ultraviolet lamp. The double bond transfer in thesubstrate molecule was highly selective. Solvents containing strongelectronegative atoms like oxygen and chlorine, such as alcohols, aldehydes, andcarbon tetrachloride, were more effective than other solvents under high lightintensity. The 1,3-proton transfer process involves photo-excitation of theSchiff base and coordination of the latter to the central metal atom of thechiral catalyst, so that the substrate molecule is placed in a stable chiralenvironment to form a transition state. The strongly electro-negative atom ofthe near-neutral solvent attracts the active α-hydrogen from the excited Schiffbase molecule to form a negatively charged delocalized π-bond structure. Thesubsequent proton addition yields more stable molec-ular structure to completethe selective proton transfer process. Among the examined chiral catalysts,divalent tin porphyrin was the most effective, and the product yield andenantiomeric excess were 98% and 91.49%, respectively. The describedphotoinduced C=N double bond transfer in N-(diphenylmethyl)-1-phenyl-ethan-1-imine is characterized by mildconditions (room temperature), high stereoselectivity, and simpleoperation.
Lanthanide triflate catalysed reactions of acetals with primary amines and cascade cyclisation reactions
Heaney, Harry,Simcox, Michael T.,Slawin, Alexandra M.Z.,Giles, Robert G.
, p. 640 - 642 (2007/10/03)
The formation of imines from acetals and primary amines can be carried out at significantly lower temperatures using scandium or lanthanide triflates as catalysts, than in the absence of a catalyst: the intermediate aminol ethers can also take part in cascade cyclisation reactions, for example using tryptamine and ethyl tryptophanate.
