Density Functional Theory Study on the Mechanism of Rh-Catalyzed Decarboxylative Conjugate Addition: Diffusion- and Ligand-Controlled Selectivity toward Hydrolysis or β-Hydride Elimination

Shi, Fuqiang

doi:10.1021/ol102974k

Cited by 14 publications

(4 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Next, the C-Rh bond in complex CP5 is protonated via four-memberedring transition state TS4 (ref. 62). Following the release of product 7b, the active intermediate CP1 is regenerated irreversibly to complete the catalytic cycle.…”

Section: Resultsmentioning

confidence: 99%

Asymmetric total synthesis of (−)-lingzhiol via a Rh-catalysed [3+2] cycloaddition

et al. 2014

View full text Add to dashboard Cite

The development of efficient reactions for the one-pot construction of bicyclic ring systems bearing two quaternary carbon centres at their bridgehead positions represents a significant challenge to synthetic chemistry. The development of new methods capable of overcoming this challenge is highly desirable, because this motif can be found in a wide range of natural products with significant biological activities. Herein, we report an efficient [3 þ 2] cycloaddition reaction between an enal and an alleno rhodium species, which was generated in situ from the corresponding enynol via a retro metal-propargylation reaction, to give [3.3.0] and [3.4.0] bicyclic systems bearing two quaternary atoms at their bridgehead positions. The developed chemistry has been successfully applied to the asymmetric total synthesis of natural product ( À )-lingzhiol (4) for the first time in 17 steps.

show abstract

Section: Resultsmentioning

confidence: 99%

Asymmetric total synthesis of (−)-lingzhiol via a Rh-catalysed [3+2] cycloaddition

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Recently, a number of computational mechanistic studies focused on the Pd(II)-catalyzed Heck reaction and the Pd(II)- or Pd(0)-catalyzed oxidative addition. , In the case of the Pd(II)/Rh(I)-catalyzed conjugate reaction, theoretical studies are rare. , Mauleon et al reported a density functional theory (DFT) study of the insertion step of Rh(I)-catalyzed asymmetric addition of boronic acids to sulfones . Miyaura reported a DFT study of the Pd(II)-catalyzed substrate coordination in enantioselective 1,4-additions of Ar 3 Bi, [ArBF 3 ]K, and ArSiF 3 to enones .…”

Section: Introductionmentioning

confidence: 99%

Conjugate Addition vs Heck Reaction: A Theoretical Study on Competitive Coupling Catalyzed by Isoelectronic Metal (Pd(II) and Rh(I))

et al. 2012

View full text Add to dashboard Cite

Density functional theory studies have been carried out to investigate the mechanism of the Pd(II)(bpy)- and Rh(I)(bpy)-catalyzed conjugate additions and their competitive Heck reactions involving α,β-unsaturated carbonyl compounds. The critical steps of the mechanism are insertion and termination. The insertion step favors 1,2-addition of the vinyl-coordinated species to generate a stable C-bound enolate intermediate, which then may isomerize to either an oxa-π-allyl species or an O-bound enolate. The termination step involves a competition between β-hydride elimination, leading to a Heck reaction product, and protonolysis reaction that gives a conjugate addition product. These two pathways are competitive in the Pd(II)-catalyzed reaction, while a preference for protonolysis has been found in the Rh(I)-catalyzed reaction. The calculations are in good agreement with the experimental observations. The potential energy surface and the rate-determining step of the β-hydride elimination are similar for both Pd(II)- and Rh(I)-catalyzed processes. The rate-determining steps of the Pd(II)- and Rh(I)-catalyzed protonolysis are different. Introduction of an N- or P-ligand significantly stabilizes the protonolysis transition state via the O-bound enolate or oxa-π-allyl complex intermediate, resulting in a reduced free energy of activation. However, the barrier of the β-hydride elimination is less sensitive to ligands. For the Rh(I)-catalyzed reaction, protonolysis is calculated to be more favorable than the β-hydride elimination for all investigated N and P ligands due to the significant ligand stabilization to the protonolysis transition state. For the Pd(II)-catalyzed reaction, the complex with monodentate pyridine ligands prefers the Heck-type product through β-hydride elimination, while the complex with bidentate N and P ligands favors the protonolysis. The theoretical finding suggests the possibility to control the selectivity between the conjugate addition and the Heck reaction by using proper ligands.

show abstract

“…However, any cationic Lewis acid (H + , H 3 O + , NH 4 + , LCu + ) caused spontaneous ring opening without a barrier when approached to the oxirane. This type of behavior is characteristic of a diffusion-controlled reaction . Since there is no maximum on the potential energy surface, the standard computational procedure for determination of the free energy barrier cannot be applied.…”

Section: Resultsmentioning

confidence: 99%

“…This type of behavior is characteristic of a diffusion-controlled reaction. 16 Since there is no maximum on the potential energy surface, the standard computational procedure for determination of the free energy barrier cannot be applied. However, as proposed by Harvey and co-workers, 17 the free energy barrier for a diffusion-controlled reaction can be estimated to be ca.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Mechanistic Studies of the CuH-Catalyzed Synthesis of α-Hydroxyallenes

2012

View full text Add to dashboard Cite

The copper hydride catalyzed S N 2′ reduction of propargyl oxiranes is an efficient method for the diastereoselective synthesis of α-hydroxyallenes. Herein, we represent a detailed computational study of this reaction using density functional theory (DFT), supported by kinetic investigations. The calculations partially validate the previously proposed reaction mechanism and explain the high anti stereoselectivity of the reaction arising from a diffusion-controlled Lewis acid activation of the epoxide−Cu−hydride complex.

show abstract

Density Functional Theory Study on the Mechanism of Rh-Catalyzed Decarboxylative Conjugate Addition: Diffusion- and Ligand-Controlled Selectivity toward Hydrolysis or β-Hydride Elimination

Cited by 14 publications

References 49 publications

Asymmetric total synthesis of (−)-lingzhiol via a Rh-catalysed [3+2] cycloaddition

Asymmetric total synthesis of (−)-lingzhiol via a Rh-catalysed [3+2] cycloaddition

Conjugate Addition vs Heck Reaction: A Theoretical Study on Competitive Coupling Catalyzed by Isoelectronic Metal (Pd(II) and Rh(I))

Mechanistic Studies of the CuH-Catalyzed Synthesis of α-Hydroxyallenes

Contact Info

Product

Resources

About