Synthesis, Resolution, Structure, and Racemization of Inherently Chiral 1,3-Alternate Azacalix[4]pyrimidines: Quantification of Conformation Mobility

doi:10.1021/jo500054v

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	Synthesis, Resolution, Structure, and Racemization of Inherently Chiral 1,3-Alternate Azacalix[4]pyrimidines: Quantification of Conformation Mobility
	Li, Jiang-Tao 1; Wang, Li-Xia 1; Wang, De-Xian 1; Zhao, Liang 2; Wang, Mei-Xiang 2
刊名	JOURNAL OF ORGANIC CHEMISTRY
	2014-03-07
卷号	79 期号:5 页码:2178-2188
ISSN号	0022-3263
DOI	10.1021/jo500054v
英文摘要	The synthesis, resolution, structure, and racemization of inherently chiral 1,3-alternate azacalix[4]pyrimidine macrocycles are reported. Site-selective halogenations of monohalo-substituted azacalix[4]pyrimidines with NBS, NCS, and NFSI produced a number of the lower-rim dihalogenated 1,3-alternate azacalix[4]pyrimidines. 1,3-Alternate azacalix[4]pyrimidines bearing two proximal substituents were AABB-type and ABCC-type inherently chiral macrocycles, and three pairs of conformationally stable P and M enantiomers with >99.5% ee were obtained from the resolution of racemic samples by chiral HPLC. Absolute configurations were determined by X-ray crystallography and were correlated with their CD spectra. The rate constants for racemization of macrocycles were measured, and enthalpies (Delta H double dagger) and entropies (Delta S double dagger) of activation were determined by the Eyring plot method. The present study revealed that a combination of two proximal substituents larger than the van der Waals radii r(w) = 1.75 angstrom (such as chlorine) and r(w) = 1.47 angstrom (such as fluorine) at the lower rim was the minimum steric requirement for the resolution and isolation of conformationally stable inherently chiral enantiomers of 1,3-alternate azacalix[4]pyrimidines at room temperature, while a combination. of two substituents larger than the van der Waals radii r(w) = 1.75 angstrom (such as chlorine) and r(w) = 1.85 angstrom (such as bromine) gave rise to an immobilized 1,3-alternate conformation up to 180 degrees C.
语种	英语
出版者	AMER CHEMICAL SOC
WOS记录号	WOS:000332756500032
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/53161]
专题	中国科学院化学研究所
通讯作者	Wang, Mei-Xiang
作者单位	1.Chinese Acad Sci, Inst Chem, CAS Key Lab Mol Recognit & Funct, Beijing Natl Lab Mol Sci, Beijing 100190, Peoples R China 2.Tsinghua Univ, Minist Educ, Key Lab Bioorgan Phosphorus Chem & Chem Biol, Beijing 100084, Peoples R China
推荐引用方式 GB/T 7714	Li, Jiang-Tao,Wang, Li-Xia,Wang, De-Xian,et al. Synthesis, Resolution, Structure, and Racemization of Inherently Chiral 1,3-Alternate Azacalix[4]pyrimidines: Quantification of Conformation Mobility[J]. JOURNAL OF ORGANIC CHEMISTRY,2014,79(5):2178-2188.
APA	Li, Jiang-Tao,Wang, Li-Xia,Wang, De-Xian,Zhao, Liang,&Wang, Mei-Xiang.(2014).Synthesis, Resolution, Structure, and Racemization of Inherently Chiral 1,3-Alternate Azacalix[4]pyrimidines: Quantification of Conformation Mobility.JOURNAL OF ORGANIC CHEMISTRY,79(5),2178-2188.
MLA	Li, Jiang-Tao,et al."Synthesis, Resolution, Structure, and Racemization of Inherently Chiral 1,3-Alternate Azacalix[4]pyrimidines: Quantification of Conformation Mobility".JOURNAL OF ORGANIC CHEMISTRY 79.5(2014):2178-2188.