enantiomers of racemic carboxylicacids was studied by 1H NMR spectroscopy. The molar ratio and the association constants of the chiral compounds with each of the enantiomers of the guests were determined by using Job plots and a non-linear least-squares fitting method, respectively. Large non-equivalent chemical shifts (up to 30.0 Hz) can be achieved in the presence of chiral amino alcohols 2 and 5
经由(R)-N-(2,3-环氧丙基)邻苯二甲酰亚胺与(R)-2-苯基甘氨醇,(1 R,2 S)-顺-1-氨基-的开环合成了四种旋光氨基醇2-茚满醇,(R)-2-氨基-1-丁醇和(S)-苯基乙胺的产率为73-93%。通过1研究了这些受体对消旋羧酸对映体的对映选择性识别。1 H NMR光谱。分别通过Job图和非线性最小二乘拟合法确定手性化合物与客体的每个对映体的摩尔比和缔合常数。在手性氨基醇2和5的存在下,可以实现较大的非等价化学位移(高达30.0 Hz)。在所用的手性受体中,发现化合物5是最好的手性转移剂,并且在确定手性羧酸的对映异构体过量方面是有效的。
Chiral calix[4]arenes bearing amino alcohol functionality as membrane carriers for transport of chiral amino acid methylesters and mandelic acid
chiral calix[4]arene derivatives bearing amino alcohol moieties at the lower rim have been synthesized from the reaction of p‐tert‐butylcalix[4]arene diester with various amino alcohols. The transport of aminoacidesters (phenylglycine, phenylalanine, and tryptophan methyl esters hydrochloride) and mandelic acid were studied through chloroform bulk liquid membrane system using chiral calix[4]arenes