Theoretical elucidation of the multi-functional synthetic methodology for switchable Ni(0)-catalyzed C-H allylations, alkenylations and dienylations with allenes

NWIPB OpenIR

	Theoretical elucidation of the multi-functional synthetic methodology for switchable Ni(0)-catalyzed C-H allylations, alkenylations and dienylations with allenes
	Liu, Yuxia; Wang, Kaifeng; Ling, Baoping; Chen, Guang; Li, Yulin; Liu, Lingjun; Bi, Siwei
	2020
发表期刊	CATALYSIS SCIENCE & TECHNOLOGY
卷号	10 期号:13
摘要	The Ni(0)-catalyzed coupling of benzimidazole with 1,1-disubstituted allenes represents a new strategy for achieving controllable C-H allylations, alkenylations and dienylations. To understand the detailed mechanisms and origins of the switchable selectivities, density functional theory (DFT) calculations were conducted. The results using atBu-substituted allene demonstrate that the formation of the allylated product involves a Ni-catalyzed C-H activation mechanism through ligand-to-ligand-hydrogen transfer (LLHT) under base-free conditions. In contrast, a Ni/NaOtBu co-promoted C-H activation mechanism is newly proposed in the presence of NaOtBu, which is remarkably different from the previously reported literature. The novel mechanism emphasizes that NaOtBu abstracts the Ni-activated heterocyclic (ipso-C)H atom followed by turnover limiting Ni slippage, and subsequently the allylated product is generated after alkene insertion and protonation. The strong electrostatic attraction between Ni and heterocyclicipso-C in the Ni slippage pre-intermediate is critical for facilitating the Ni slippage. Once formed, the allylated product, assisted by NaOtBu, further evolves into a more stable alkenylated isomer. Employing a (tert-butyldimethylsilyl)-ether substituted allene as the substrate, the NaOtBu-induced chemoselectivity for dienylationvs.alkenylation was also probed and it was found that the O(tBu)-HMIDLINE HORIZONTAL ELLIPSISO(Si) hydrogen bonding interaction in the C-O(Si) cleavage pre-intermediate remarkably weakens the adjacent C-O(Si) sigma-bond, thereby resulting in an exclusive C-O(Si) cleaved dienylation product. Further theoretical predictions suggest that the chemoselectivity might be reversed by replacingtBu in NaOtBu by the withdrawing C(CF3)(3)group.
文献类型	期刊论文
条目标识符	http://210.75.249.4/handle/363003/60299
专题	中国科学院西北高原生物研究所
推荐引用方式 GB/T 7714	Liu, Yuxia,Wang, Kaifeng,Ling, Baoping,et al. Theoretical elucidation of the multi-functional synthetic methodology for switchable Ni(0)-catalyzed C-H allylations, alkenylations and dienylations with allenes[J]. CATALYSIS SCIENCE & TECHNOLOGY,2020,10(13).
APA	Liu, Yuxia.,Wang, Kaifeng.,Ling, Baoping.,Chen, Guang.,Li, Yulin.,...&Bi, Siwei.(2020).Theoretical elucidation of the multi-functional synthetic methodology for switchable Ni(0)-catalyzed C-H allylations, alkenylations and dienylations with allenes.CATALYSIS SCIENCE & TECHNOLOGY,10(13).
MLA	Liu, Yuxia,et al."Theoretical elucidation of the multi-functional synthetic methodology for switchable Ni(0)-catalyzed C-H allylations, alkenylations and dienylations with allenes".CATALYSIS SCIENCE & TECHNOLOGY 10.13(2020).