How Does Palladium-Amino Acid Cooperative Catalysis Enable Regio- and Stereoselective C(sp(3))-H Functionalization in Aldehydes and Ketones? A DFT Mechanistic Study

CORC > 生态环境研究中心 > 中国科学院生态环境研究中心 > 环境化学与生态毒理学国家重点实验室

	How Does Palladium-Amino Acid Cooperative Catalysis Enable Regio- and Stereoselective C(sp(3))-H Functionalization in Aldehydes and Ketones? A DFT Mechanistic Study
	Liu, Wenjing; Zheng, Jia; Liu, Zheyuan; Hu, Wenping; Wang, Xiaotai; Dang, Yanfeng
刊名	ACS CATALYSIS
	2018-08-01
卷号	8 期号:8 页码:7698-7709
关键词	palladium catalysis metal-organic cooperative catalysis C-H activation reaction mechanism regio- and stereoselectivities
ISSN号	2155-5435
文献子类	Article
英文摘要	Density functional theory computations have elucidated the detailed mechanism and intriguing selectivities of C(sp(3))-H activation and arylation of aldehydes and ketones promoted by palladium amino acid cooperative catalysis. The amino acid cocatalyst takes up the carbonyl substrate by a condensation reaction to form an imine acid, which acts as a transient directing reagent and metathesizes with Pd(OAc)(2) (the precatalyst) to initiate active Pd(II) complexes. The reaction then proceeds through C-H bond activation, oxidative addition of Pd(II) by iodobenzene, and reductive elimination from Pd(IV) completing C-C bond formation, followed by ligand exchange to regenerate the active Pd(II) catalyst and release the arylated imine acid which continues on hydrolysis to give the final product and regenerate the amino acid cocatalyst. The C-H activation step via concerted metalation deprotonation (CMD), which is rate-and selectivity-determining, favors palladacyclic transition states with a minimum chelate ring strain and an optimal Pd(d)/C-H(a) orbital interaction. This finding reveals the origins of the regioselectivities that favor (1) the benzylic C(sp(3))-H over ortho-phenyl C(sp(2))-H activation for aromatic aldehydes and (2) the beta-primary C(sp(3))-H over gamma-primary C(sp(3))-H activation for aliphatic ketones. Incorporation of a chiral amino acid into the catalyst allows for enantioselective benzylic C(sp(3))-H arylation of aromatic aldehydes, and the enantioselectivity arises from steric and torsional strains that discriminate between the diastereomeric transition states. The computational results demonstrate rich experimental theoretical synergy and provide useful insights for the further development of C H functionalization and metal organic cooperative catalysis.
内容类型	期刊论文
源URL	[http://ir.rcees.ac.cn/handle/311016/40957]
专题	生态环境研究中心_环境化学与生态毒理学国家重点实验室
推荐引用方式 GB/T 7714	Liu, Wenjing,Zheng, Jia,Liu, Zheyuan,et al. How Does Palladium-Amino Acid Cooperative Catalysis Enable Regio- and Stereoselective C(sp(3))-H Functionalization in Aldehydes and Ketones? A DFT Mechanistic Study[J]. ACS CATALYSIS,2018,8(8):7698-7709.
APA	Liu, Wenjing,Zheng, Jia,Liu, Zheyuan,Hu, Wenping,Wang, Xiaotai,&Dang, Yanfeng.(2018).How Does Palladium-Amino Acid Cooperative Catalysis Enable Regio- and Stereoselective C(sp(3))-H Functionalization in Aldehydes and Ketones? A DFT Mechanistic Study.ACS CATALYSIS,8(8),7698-7709.
MLA	Liu, Wenjing,et al."How Does Palladium-Amino Acid Cooperative Catalysis Enable Regio- and Stereoselective C(sp(3))-H Functionalization in Aldehydes and Ketones? A DFT Mechanistic Study".ACS CATALYSIS 8.8(2018):7698-7709.