Asymmetric Michael reactions of α-substituted acetates with cyclic enones catalyzed by multifunctional chiral Ru amido complexes

Ikariya, Takao; Wang, Hui; Watanabe, Minoru; Murata, Kunihiko

doi:10.1016/j.jorganchem.2003.12.002

Cited by 51 publications

(11 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ikariya and co‐workers successfully applied the MNH system to conjugate addition of various donors to acceptors. Excellent enantioselectivies and high activities were achieved in the conjugate addition of malonates to cyclic enones (Scheme ),107a,c,d 1,3‐dicarbonyl compounds to nitroalkenes (Scheme ),107b α‐substituted cyanoacetates to acetylenic esters (Scheme ),107e and α‐cyanoacetates to azodicarboxylates (Scheme )107f by using amido Ru complexes 188 – 190 and Ir complex 175 as catalysts. According to experimental and computational studies, the authors proposed a plausible mechanism for the additions (Scheme ) 108.…”

Section: Mnh Catalysismentioning

confidence: 99%

The NH Functional Group in Organometallic Catalysis

2013

View full text Add to dashboard Cite

The organometallic approach is one of the most active topics in catalysis. The application of NH functionality in organometallic catalysis has become an important and attractive concept in catalyst design. NH moieties in the modifiers of organometallic catalysts have been shown to have various beneficial functions in catalysis by molecular recognition through hydrogen bonding to give catalyst-substrate, ligand-ligand, ligand-catalyst, and catalyst-catalyst interactions. This Review summarizes recent progress in the development of the organometallic catalysts based on the concept of cooperative catalysis by focusing on the NH moiety.

show abstract

Section: Mnh Catalysismentioning

confidence: 99%

The NH Functional Group in Organometallic Catalysis

2013

View full text Add to dashboard Cite

show abstract

“…When b-keto esters and 1,3-diketones were used as Michael donors in the reaction with nitroalkenes, the stereochemical outcome of the reaction was notably influenced by the structure of the reagents (Scheme 4) [23,24]. The enantioselectivity of the reaction was strongly affected by the bulkiness of the acyl group in the keto esters, increasing in the order CH 3 \ C 2 H 5 \ CH(CH 3 ) 2 \ C 6 H 5 .…”

Section: Enantioselective Michael Addition Of 13-dicarbonyl Compoundmentioning

confidence: 99%

“…The chiral amido complexes have sufficient Brønsted basicity to readily react with several acidic compounds such as nitromethane, acetone, dimethyl manolate, and acetoacetate, leading to the corresponding amine complexes bearing a metal bonded carbon nucleophiles (Scheme 2) [20][21][22][23][24][25]. All reactions gave equilibrium mixtures of the corresponding amido complexes (1 or 2) and amine complexes (3 or 4) in solution.…”

Section: Introductionmentioning

confidence: 99%

Bifunctional Transition Metal-Based Molecular Catalysts for Asymmetric C–C and C–N Bond Formation

Ikariya

Gridnev

2010

Top Catal

Self Cite

View full text Add to dashboard Cite

This paper describes recent advances in the development of the asymmetric catalytic reactions promoted by conceptually new bifunctional molecular catalysts. These reactions include the enantioselective Michael addition of 1,3-dicarbonyl compounds to cyclic enones and nitroalkenes, and the enantioselective direct amination of a-cyanoacetates to diazoesters. The nature of the catalyst in each particular case was delicately tuned by adjusting the combination of the central metal together with the structures of the cooperating ligands, applied solvents, and the reaction conditions to achieve the utmost catalytic performance in terms of reactivity and selectivity. In the presence of the optimized catalyst the addition reactions proceeded smoothly with a 1:1 M ratio of the reagents to give the corresponding chiral adducts with excellent yields and ee's. Preliminary mechanistic studies based on NMR spectroscopy and DFT analysis showed that the key step of the catalytic cycle is the interaction of the bifunctional catalyst with a pronucleophilic reagent that leads to stereoselective formation of C-, O-, or N-bound amino complexes. The resulting amino catalyst bearing metal-bound nucleophiles readily reacts with an electrophile that acquires the reactive conformation through the cooperative effect of the acidic NH protons. This results in the formation of a C-C or a C-N bond yielding the corresponding products in a highly stereoselective manner.

show abstract

“…Moreover, α‐nitroacetate also provides profound derivation after the initial reaction, such as decarboxylation and denitration . However, currently this nucleophile received relatively less attention in the case of catalytic enantioselective Michael addition in comparison with other often‐used donors . Only limited electrophilic components have been investigated, including α,β‐unsaturated enones, β,γ‐unsaturated α‐ketoesters, maleimides, nitroolefins, and o ‐quinone methides …”

Section: Introductionmentioning

confidence: 99%

“…10,14 However, currently this nucleophile received relatively less attention in the case of catalytic enantioselective Michael addition in comparison with other often-used donors. [14][15][16][17][18][19][20][21][22][23][24][25][26][27] Only limited electrophilic components have been investigated, including α,β-unsaturated enones, 14,17-21 β,γ-unsaturated α-ketoesters, 15,16,22,23 maleimides, 24 nitroolefins, 25,26 and o-quinone methides. 27 On the other hand, in contrast with those well-documented acceptors (especially α,β-unsaturated enones/enals and nitroalkenes), α,β-unsaturated acid derivative [28][29][30][31][32][33][34] remains a type of less-explored electrophilic partner presumably due to their relatively lower reactivity in the case of organocatalytic conjugate addition reactions.…”

Section: Introductionmentioning

confidence: 99%

Highly enantioselective Michael addition of α‐nitroacetate to α,β‐unsaturated pyrazolamide catalyzed by a bifunctional squaramide

Liu

Shi

et al. 2018

Chirality

View full text Add to dashboard Cite

A highly enantioselective (91‐ > 99% ee) Michael addition of α‐nitroacetate to α,β‐unsaturated pyrazolamide was developed in the presence of a bifunctional squaramide. Satisfactory isolated yields (42%‐99%) have been achieved with a wide range of α,β‐unsaturated pyrazolamides, albeit acceptor of this type displayed poor reactivity in the precedent reports. The adducts resulting from this protocol are useful synthetic intermediates for further synthetic modification.

show abstract

Asymmetric Michael reactions of α-substituted acetates with cyclic enones catalyzed by multifunctional chiral Ru amido complexes

Cited by 51 publications

References 37 publications

The NH Functional Group in Organometallic Catalysis

The NH Functional Group in Organometallic Catalysis

Bifunctional Transition Metal-Based Molecular Catalysts for Asymmetric C–C and C–N Bond Formation

Highly enantioselective Michael addition of α‐nitroacetate to α,β‐unsaturated pyrazolamide catalyzed by a bifunctional squaramide

Contact Info

Product

Resources

About