Computational insights into Ir(iii)-catalyzed allylic C–H amination of terminal alkenes: mechanism, regioselectivity, and catalytic activity

Published on May 24, 2021in RSC Advances3.119
· DOI :10.1039/D1RA03842G
Deng Pan (DUT: Dalian University of Technology), Gen Luo13
Estimated H-index: 13
(Anda: Anhui University)
+ 2 AuthorsYi Luo26
Estimated H-index: 26
(DUT: Dalian University of Technology)
Computational studies on Ir(III)-catalyzed intermolecular branch-selective allylic C–H amination of terminal olefins with methyl dioxazolone have been carried out to investigate the mechanism, including the origins of regioselectivity and catalytic activity difference. The result suggests that the reaction proceeds through generation of active species, alkene coordination, allylic C–H activation, decarboxylation, migratory insertion, and protodemetalation. The presence of AgNTf2 could thermodynamically promote the formation of catalytically active species [Cp*Ir(OAc)]+. Both the weaker Ir–C(internal) bond and the closer interatomic distance of N⋯C(internal) in the key allyl-Ir(V)-nitrenoid intermediate make the migratory insertion into Ir–C(internal) bond easier than into the Ir–C(terminal) bond, leading to branch-selective allylic C–H amidation. The high energy barrier for allylic C–H activation in the Co system could account for the observed sluggishness, which is mainly ascribed to the weaker coordination capacity of alkenes to the triplet Cp*Co(OAc)+ and the deficient metal⋯H interaction to assist hydrogen transfer.
#1Seung Youn HongH-Index: 6
#2Hwang Yeongyu (KAIST)H-Index: 4
Last. Sukbok Chang (KAIST)H-Index: 90
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ConspectusCatalytic reactions that construct carbon-nitrogen bonds are one of central themes in both synthetic and medicinal chemistry since the obtainable nitrogen-containing motifs are commonly encountered in natural products and have also seen a growing prominence as key structural features in marketed drugs and preclinical candidates. Pd-catalyzed cross-couplings, such as Buchwald-Hartwig amination, are at the forefront of such synthetic methods in practical settings. However, they require p...
1 CitationsSource
#1Jeonghyo LeeH-Index: 2
#2Seongho Jin (KAIST)H-Index: 2
Last. Sukbok Chang (KAIST)H-Index: 90
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Alkanes are an abundant and inexpensive source of hydrocarbons; thus, development of new methods to convert the hydrocarbon feedstocks to value-added chemicals is of high interest. However, it is challenging to achieve such transformation in a direct and selective manner mainly due to the intrinsic inertness of their C-H bonds. We herein report a tailored Cp*Co(III)(LX)-catalyzed efficient and site-selective intermolecular amidation of unactivated hydrocarbons including light alkanes. Electronic...
2 CitationsSource
#1Yang Yu (DUT: Dalian University of Technology)H-Index: 3
#2Gen Luo (Anda: Anhui University)H-Index: 13
Last. Yi Luo (DUT: Dalian University of Technology)H-Index: 26
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2 CitationsSource
#1Hwang Yeongyu (KAIST)H-Index: 4
#2Hoimin Jung (KAIST)H-Index: 11
Last. Sukbok Chang (KAIST)H-Index: 90
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Transition metal-catalyzed nitrenoid transfer reaction is one of the most attractive methods for installing a new C–N bond into diverse reactive units. While numerous selective aminations have been...
6 CitationsSource
#1Yang Yu (DUT: Dalian University of Technology)H-Index: 3
#2Gen Luo (Anda: Anhui University)H-Index: 13
Last. Yi Luo (DUT: Dalian University of Technology)H-Index: 91
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A comprehensive DFT study has been performed on the mechanism of Rh-catalysed C‒H amination of N-arylbenzamide with N-chloromorpholine. The catalytic cycle starting from the N‒H deprotonation of N-arylbenzamide was ruled out due to the inconsistence between the calculated and experimentally observed rate-determining step. Instead, the CsOAc induced pre-deprotonated form of N-arylbenzamide participates in the catalytic cycle. The reaction then goes through C‒H activation via concerted-metalation ...
#1Robert J. Harris (Emory University)H-Index: 2
#2Jiyong Park (KAIST)H-Index: 14
Last. Simon B. Blakey (Emory University)H-Index: 20
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Herein the mechanism of catalytic allylic C–H amination reactions promoted by Cp*Rh complexes is reported. Reaction kinetics experiments, stoichiometric studies, and DFT calculations demonstrate th...
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#1Oleg I. Afanasyev (A. N. Nesmeyanov Institute of Organoelement Compounds)H-Index: 7
#2Ekaterina A. Kuchuk (A. N. Nesmeyanov Institute of Organoelement Compounds)H-Index: 4
Last. Denis Chusov (HSE: National Research University – Higher School of Economics)H-Index: 15
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Reductive amination plays a paramount role in pharmaceutical and medicinal chemistry owing to its synthetic merits and the ubiquitous presence of amines among biologically active compounds. It is one of the key approaches to C–N bond construction due to its operational easiness and a wide toolbox of protocols. Recent studies show that at least a quarter of C–N bond-forming reactions in the pharmaceutical industry are performed via reductive amination. This Review concisely compiles information o...
54 CitationsSource
#1Rong-Hua Wang (NKU: Nankai University)H-Index: 2
#2Yuxin Luan (NKU: Nankai University)H-Index: 1
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#1Ali Nasrallah (Institut de Chimie des Substances Naturelles)H-Index: 3
#2Vincent Boquet (Institut de Chimie des Substances Naturelles)H-Index: 2
Last. Philippe Dauban (Institut de Chimie des Substances Naturelles)H-Index: 35
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: A practical general method for asymmetric intermolecular benzylic C(sp3 )-H amination has been developed by combining the pentafluorobenzyl sulfamate PfbsNH2 with the chiral rhodium(II) catalyst Rh2 (S-tfptad)4 . Various substrates can be used as limiting components and converted to benzylic amines with excellent yields and high levels of enantioselectivity. Additional key features for the reaction are the low catalyst loading and the ability to remove the Pfbs group under mild conditions to g...
14 CitationsSource
#1Tobias KnechtH-Index: 12
#2Shobhan MondalH-Index: 7
Last. Frank GloriusH-Index: 124
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: Herein, we report the redox-neutral, intermolecular, and highly branch-selective amidation of allylic C-H bonds enabled by Cp*IrIII catalysis. A variety of readily available carboxylic acids were converted into the corresponding dioxazolones and efficiently coupled with terminal and internal olefins in high yields and selectivities. Mechanistic investigations support the formation of a nucleophilic IrIII -allyl intermediate rather than the direct insertion of an Ir-nitrenoid species into the a...
36 CitationsSource
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