Density Functional Theory Study of the Mechanism of the   Rhodium(I)-Catalyzed Conjugated Diene Assisted Allylic C-H Bond   Activation and Addition to Alkenes Using Ene-2-dienes As Substrates

doi:10.1021/om300523u

CORC > 北京大学 > 化学与分子工程学院

	Density Functional Theory Study of the Mechanism of the Rhodium(I)-Catalyzed Conjugated Diene Assisted Allylic C-H Bond Activation and Addition to Alkenes Using Ene-2-dienes As Substrates
	Li, Qian ; Yu, Zhi-Xiang
刊名	organometallics
	2012
关键词	5+2 CYCLOADDITION REACTIONS CROSS-COUPLING REACTIONS CARBON-HYDROGEN BONDS INTRAMOLECULAR 4+2 CATALYZED CYCLOISOMERIZATION REDUCTIVE ELIMINATION ORGANIC-SYNTHESIS AROMATIC IMINES ALKYL-HALIDES RING-SYSTEMS
DOI	10.1021/om300523u
英文摘要	Recently we reported the first conjugated diene. assisted, rhodium-catalyzed allylic C-H bond activation and addition to alkenes to synthesize multifunctional tetrahydropyrroles, tetrahydrofurans, and cyclopentanes from ene-2-diene substrates, with good to excellent diastereoselectivities. Here we report a DFT study of the mechanism of this reaction, aiming to obtain a detailed potential energy surface, to understand factors determining its stereochemistry, and to determine why conjugated diene is very critical for the success of this reaction. DFT calculations unveiled that the catalytic cycle of this reaction involves a sequence of substrate catalyst complex formation, allylic C-H activation, alkene insertion into the Rh-H bond, and di-pi-allyl-assisted C(sp(3))-Rh-C(sp(3)) reductive elimination, among which the C-H activation and alkene insertion steps are reversible. The main reason for the formation of the cis-divinyl product is that the irreversible reductive elimination transition state from the bis-allylic Rh complex favors a cis 5/5 bicyclic conformation to reduce the ring strain. Moreover, formation of the cis-divinyl product is also assisted by the alkene coordination to the Rh center in the reductive elimination transition state. DFT insights revealed that the conjugated diene, which is very critical for the target reaction, disfavors the double-bond isomerization and facilitates the reductive elimination for the bis-allylic Rh complex, causing the C-H activation and alkene insertion to occur. The computational results showed that the bridgehead double-bond distortion, as suggested by the Bredt's rule, is responsible for not generating the type II [4+2] cycloadducts from ene-2-dienes.; Chemistry, Inorganic & Nuclear; Chemistry, Organic; SCI(E); EI; 0; ARTICLE; 14; 5185-5195; 31
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/232644]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	Li, Qian,Yu, Zhi-Xiang. Density Functional Theory Study of the Mechanism of the Rhodium(I)-Catalyzed Conjugated Diene Assisted Allylic C-H Bond Activation and Addition to Alkenes Using Ene-2-dienes As Substrates[J]. organometallics,2012.
APA	Li, Qian,&Yu, Zhi-Xiang.(2012).Density Functional Theory Study of the Mechanism of the Rhodium(I)-Catalyzed Conjugated Diene Assisted Allylic C-H Bond Activation and Addition to Alkenes Using Ene-2-dienes As Substrates.organometallics.
MLA	Li, Qian,et al."Density Functional Theory Study of the Mechanism of the Rhodium(I)-Catalyzed Conjugated Diene Assisted Allylic C-H Bond Activation and Addition to Alkenes Using Ene-2-dienes As Substrates".organometallics (2012).