Mechanism and Selectivity in the Pd-Catalyzed Difunctionalization of   Isoprene

doi:10.1021/acs.joc.6b01317

CORC > 北京大学 > 化学与分子工程学院

	Mechanism and Selectivity in the Pd-Catalyzed Difunctionalization of Isoprene
	Xu, Liping ; Zhang, Xin ; McCammant, Matthew S. ; Sigman, Matthew S. ; Wu, Yun-Dong ; Wiest, Olaf
刊名	JOURNAL OF ORGANIC CHEMISTRY
	2016
关键词	PYRIDINE-OXAZOLINE LIGANDS DENSITY FUNCTIONALS TERMINAL 1,3-DIENES TRANSITION-ELEMENTS ALKENYL ALCOHOLS 1,4-DIFUNCTIONALIZATION INSIGHTS DIENES ACIDS
DOI	10.1021/acs.joc.6b01317
英文摘要	The three-component coupling of isoprene, an alkenyl triflate, and styrenylboronic acid catalyzed by a palladium pyrox complex affords access to skipped dienes from simple chemical feedstocks. Unfortunately, the transformation proceeds with only moderate selectivity and yields. The reaction mechanism and factors responsible for the resulting regioselectivity were elucidated using M06/SDD/6-311++G(d,p) + SMD calculations. Distortion of the palladium coordination sphere in the transition structure of the migratory insertion step is found to control the 4,1- vs 1,x-selectivity. The calculated Delta Delta G double dagger of 1.0 kcal/mol for this step is in excellent agreement with the experimentally observed selectivity of 1:9.9 disfavoring the 4,1-product. The transmetalation was found to be the regioselectivity determining step for the formation of the 1,2- vs 1,4-addition products. Systematic conformational searches for the transmetalation transition structure revealed a series of steric interactions between the t-Bu substituent on the ligand and the substrates in the model system that are balanced by additional repulsive interactions between the substrates and the pyridyl portion of the ligand. The combination of these effects leads to the low to moderate 1,2 vs 1,4-selectivity in the experimentally studied system.; U.S. National Science Foundation [NSF CHE1058075]; National Science Foundation of China [NSFC 21133002]; Shenzhen Peacock Program [JCYJ20140509093817689]; Nanshan District [KC2014ZDZJ0026A]; National Institute of Health [R01GM063540]; SCI(E); EI; PubMed; ARTICLE; owiest@nd.edu; 17; 7604-7611; 81
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/448008]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	Xu, Liping,Zhang, Xin,McCammant, Matthew S.,et al. Mechanism and Selectivity in the Pd-Catalyzed Difunctionalization of Isoprene[J]. JOURNAL OF ORGANIC CHEMISTRY,2016.
APA	Xu, Liping,Zhang, Xin,McCammant, Matthew S.,Sigman, Matthew S.,Wu, Yun-Dong,&Wiest, Olaf.(2016).Mechanism and Selectivity in the Pd-Catalyzed Difunctionalization of Isoprene.JOURNAL OF ORGANIC CHEMISTRY.
MLA	Xu, Liping,et al."Mechanism and Selectivity in the Pd-Catalyzed Difunctionalization of Isoprene".JOURNAL OF ORGANIC CHEMISTRY (2016).