13652-38-5Relevant academic research and scientific papers
13 C shieldings in syn and anti aldimines and ketimines
Fraser, Robert R.,Banville, Jacques,Akiyama, Fuminori,Chuaqui-Offermanns, Noemi
, p. 705 - 709 (2007/10/02)
The 13 C chemical shifts in a variety of aldimines and in both acyclic and cyclic ketimines have been examined.A comparison of the shieldings at the α carbons in syn versus anti stereoisomers shows a consistent upfield shift of 8-11 ppm in the syn isomer.The greater magnitude found in imines vs. oximes or hydrazones is a clear indication of a steric origin for the differential shieldings.The shifts in the imines of cyclohexanones exhibited stereochemically dependent effects of methyl substitution, very similar to those in analogous oxime and hydrazone derivatives.Chemical shift differences in the syn isomers of the α-phenetylimines of chiral aldimines and ketimines allow a facile measurement of diastereomer ratios for such compounds.
