Enantioselective Construction of Dihydropyran‐Fused Indoles through Chiral Calcium Phosphate Catalyzed Oxo‐Hetero‐Diels–Alder Reactions by Using 2‐Oxoindolin‐3‐ylidenes as Heterodienes

Mao, Zhijie; Li, Weipeng; Shi, Yan; Mao, Haibin; Lin, Aijun; Zhu, Chengjian; Cheng, Yixiang

doi:10.1002/chem.201301039

Cited by 49 publications

(20 citation statements)

References 83 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[1][2][3][4][5][6][7][8][9][10] Recent attention has focussed on combining these catalysts with a range of metals to explore new modes of activation. Asymmetric examples of this have been reported using metal salts formed from Ag(I), [11][12][13][14][15][16][17][18] Mg(II), [19][20][21][22] Ca(II), [23][24][25][26][27][28][29][30] Au(I), 31 Mn(III), 32 Fe(III), 33 Cu(I) 34 etc. 7,[35][36][37][38] and CPA counteranions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The True Catalyst Revealed: The Intervention of Chiral Ca and Mg Phosphates in Brønsted Acid Promoted Asymmetric Mannich Reactions

Simón

Paton

2018

J. Am. Chem. Soc.

View full text Add to dashboard Cite

The acetylacetone-benzaldimine Mannich reaction catalyzed by Mg(II) and Ca(II) salts of chiral phosphoric acids (CPA) has been investigated computationally by QM/MM methods. Enantioselectivity in this reaction is both larger than and in the opposite sense to that observed for the same reaction catalyzed by the protic CPA catalyst alone. We present a mechanistic model from which the characteristic differences between these metal and metal-free catalysts, which can coexist in the same reaction mixture, can be understood. Alkaline earth salts with chiral phosphate counterions are found to be more catalytically active than the protic form, and the Ca(II) and Mg(II) CPA salts react via different mechanisms, with a higher coordination number favored by calcium over magnesium. In the well-ordered chiral cavities around these metal centers, asymmetric induction arises from the steric interaction with the imine protecting group in the unfavorable pathway, with both substrates adopting well-defined conformations. These mechanistic models have allowed us to rationalize the stereochemical outcome across a range of bimolecular reactions promoted by divalent metal phosphates formed with different CPAs.

show abstract

Section: Introductionmentioning

confidence: 99%

“…The participation of (CPA)2M complexes is also suggested in other work. 23,27,28 The participation of 1:1 CPA-M 2+ complexes has also been suggested. Luo described the combination of a CPA organocatalyst with MgCl2 in the intramolecular tertaminocyclization of 2-arylidenemalonates.…”

Section: Introductionmentioning

confidence: 99%

The True Catalyst Revealed: The Intervention of Chiral Ca and Mg Phosphates in Brønsted Acid Promoted Asymmetric Mannich Reactions

Simón

Paton

2018

J. Am. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…Very recently, Liu and coworkers reported the amine‐catalyzed [4 + 2] cycloaddition of isatin derived alkenes and allenoates to form dihydropyranol [2,3‐ b ]indol . Due to its interesting biological and pharmacological activities, dihydropyranol [2,3‐ b ]indol has attracted more and more attention …”

Section: Introductionmentioning

confidence: 99%

Mechanisms of DABCO‐ and DMAP‐catalyzed [2 + 4] cycloaddition reactions of methylallenoate with methyleneindolonone: A DFT study

Liu

2017

Int J of Quantum Chemistry

View full text Add to dashboard Cite

The mechanisms and stereoselectivities of the [2 + 4] cycloaddition reaction of methylallenoate R1 with methyleneindolonone R2 catalyzed by DABCO (Equation 1) and DMAP (Equation 2) organocatalysts have been examined with density functional theory (M06‐2X) calculations. Several possible reaction pathways (paths 1a, 1b, and 1c for Equation 1 and paths 2a and 2b for Equation 2) were located and compared. The results of our study reveal that for both reactions, three reaction stages have been characterized: nucleophilic addition of the catalyst (DABCO or DMAP) to R1 (Stage I), addition of the other reactant R2 (Stage II), intramolecular cycloaddition and liberation of the catalyst (DABCO or DMAP) afforded the final product (Stage III). For the DABCO‐catalyzed cycloaddition, we predict that path 1a leading to P(E) is the most energy favorable pathway among the three possible pathways. The carbon–carbon bond formation step is the rate‐determining step (ΔG‡=23.6 kcal/mol). With DMAP catalyst, the same reaction gave P(Z) as the major product. The barrier for the rate‐determining step (addition of R1 to DMAP) is 25.8 kcal/mol. The calculated results are in agreement with the experimental findings. Moreover, for both reactions, the analysis of global reactivity indexes has been carried out to examine the role of catalyst. The present study should provide a general mechanistic framework for the rational design of this kind of reactions.

show abstract

“…These substructures are found in many biologically active natural products and pharmaceuticals, making them highly desirable targets in medicinal chemistry (Scheme ) . Most recent methods in the literature focus on the synthesis of chiral hydropyrano[2,3‐ b ]indoles via N‐heterocyclic carbene (NHC) catalysis,, calcium phosphate catalysis, tertiary amine catalysis or N,N′ ‐dioxide/metal catalysis ,. While several methods exist for constructing the isomeric skeleton, few methods are available to stereoselectively construct chiral hydropyrano[3,2‐ b ]indoles, which is another intriguing combination type of synthetically important indole and hydropyran motifs .…”

Section: Introductionmentioning

confidence: 99%

Stereoselective Synthesis of Hydropyrano[3,2‐b]indoles via Organocatalytic Asymmetric Inverse‐Electron‐Demand Oxa‐Diels–Alder Reaction

Yang

Huang

et al. 2016

Adv Synth Catal

View full text Add to dashboard Cite

Enantio‐ and diastereoselective inverse‐electron‐demand oxa‐Diels–Alder reactions are described between (Z)‐2‐ylideneoxindoles and aldehydes in the presence of a chiral secondary amine catalyst. The corresponding hydropyrano[3,2‐b]indoles are produced in up to 77% yield with up to 99% ee. Convenient synthetic transformations of the products readily lead to pharmacologically interesting scaffolds bearing multiple functional groups. This method may also provide an alternative approach for the asymmetric synthesis of 2‐spirocyclo‐3‐oxindoles.

show abstract

Enantioselective Construction of Dihydropyran‐Fused Indoles through Chiral Calcium Phosphate Catalyzed Oxo‐Hetero‐Diels–Alder Reactions by Using 2‐Oxoindolin‐3‐ylidenes as Heterodienes

Cited by 49 publications

References 83 publications

The True Catalyst Revealed: The Intervention of Chiral Ca and Mg Phosphates in Brønsted Acid Promoted Asymmetric Mannich Reactions

The True Catalyst Revealed: The Intervention of Chiral Ca and Mg Phosphates in Brønsted Acid Promoted Asymmetric Mannich Reactions

Mechanisms of DABCO‐ and DMAP‐catalyzed [2 + 4] cycloaddition reactions of methylallenoate with methyleneindolonone: A DFT study

Stereoselective Synthesis of Hydropyrano[3,2‐b]indoles via Organocatalytic Asymmetric Inverse‐Electron‐Demand Oxa‐Diels–Alder Reaction

Contact Info

Product

Resources

About