Dienamine Catalysis: An Emerging Technology in Organic Synthesis

Ramachary, Dhevalapally B.; Reddy, Y. Vijayendar

doi:10.1002/ejoc.201101157

Cited by 241 publications

(69 citation statements)

References 117 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Jørgensen 9a recently introduced a new dual activation mode of α,β-unsaturated aldehydes 1 , via dienamine formation, and activation of nitro-olefins 2 , via hydrogen-bonding, affording fully substituted cyclobutanes 4 by an organocatalytic formal [2 + 2]-cycloaddition catalyzed by a computationally designed catalyst 3 (Scheme 2a). In other work, Jørgensen 10c utilized trienamine-activated dienes, generated in situ from α,β,γ,δ,-dienyl aldehydes 5 and chiral aminocatalyst 7 , in thio-Diels-Alder reactions with thiocarbonyls 6 to access highly enantioenriched dihydrothiopyrans 8 (Scheme 2b).…”

Section: Iminium/enamine Catalysismentioning

confidence: 99%

“…This activation mode has led to the development of a vast number of asymmetric α-functionalizations of aldehydes and ketones with carbon- and heteroatom-based electrophiles. 8 This concept has been extended to unsaturated carbonyl systems resulting in the discovery of dienamine, 9 trienamine, 10 and more recently tetraenamine 11 activation modes.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The ever-expanding role of asymmetric covalent organocatalysis in scalable, natural product synthesis

Abbasov

Romo

2014

Nat. Prod. Rep.

View full text Add to dashboard Cite

Following the turn of the millennium, the role of asymmetric covalent organocatalysis has developed into a scalable, synthetic paradigm galvanizing the synthetic community toward utilization of these methods toward more practical, metal-free syntheses of natural products. A myriad of reports on asymmetric organocatalytic modes of substrate activation relying on small, exclusively organic molecules are delineating what has now become the multifaceted field of organocatalysis. In covalent catalysis, the catalyst and substrate combine to first form a covalent, activated intermediate that enters the catalytic cycle. Following asymmetric bond formation, the chiral catalyst is recycled through hydrolysis or displacement by a pendant group on the newly formed product. Amine- and phosphine-based organocatalysts are the most common examples that have led to a vast array of reaction types. This Highlight provides a brief overview of covalent modes of organocatalysis and applications of scalable versions of these methods applied to the total synthesis of natural products including examples from our own laboratory.

show abstract

Section: Iminium/enamine Catalysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The ever-expanding role of asymmetric covalent organocatalysis in scalable, natural product synthesis

Abbasov

Romo

2014

Nat. Prod. Rep.

View full text Add to dashboard Cite

show abstract

“…Yields are those of isolated pure diastereomers 7; enantiomeric excesses were determined by chiral HPLC analysis; diastereomeric ratios were calculated from the yields of isolated compounds 7 and their diastereomers addition to propanal. We also evaluated the use of the branched α,β-unsaturated aldehyde, 4-methylpent-2-enal via α-selective dienamine catalysis, 15 which led to the formation of the desired allyl-substituted spiro-indanone 7m in a somewhat lower yield, but still with good levels of stereocontrol. The absolute configuration of 7b was determined to be 10S,11S,12R by X-ray crystallographic analysis (Figure 2).…”

Section: Figure 1 Selected Examples Of Biologically Active Indanonesmentioning

confidence: 99%

Asymmetric Synthesis of Oxa-spirocyclic Indanones with Structural Complexity via an Organocatalytic Michael–Henry–Acetalization Cascade

Xie

Peng

Leng

et al. 2013

Synlett

View full text Add to dashboard Cite

Abstract:The highly enantioselective preparation of drug-like oxa-spirocyclic indanone derivatives employing a multicomponent cascade reaction is described. This approach utilizes an organocatalytic Michael reaction followed by a Henry-acetalization sequence that yields the desired chiral spirocyclic backbone, bearing four contiguous stereogenic centers and multiple functional groups, in good yields and high stereoselectivities (up to 99% ee and 95:5 dr).Key words: organocatalysis, chiral indanone, oxa-spirocycles, tandem reactions, asymmetric synthesis Chiral indanone is a commonly occurring framework found in many natural products and pharmaceuticals. 1 A range of biologically active compounds possessing this privileged scaffold are well documented. 2 For instance, tripartin, a new dichlorinated indanone found in actinomycete bacteria, displays a potent and specific histone demethylase inhibiting effect. 2a The natural indanone products, pterosin C and paucifloral F, were isolated from the aerial parts of Acrostichum aureum 2b and the stem barks of Vatica pauciflora, 2c respectively. The recent discovery of spiroindanone-based hybrid molecule and its analogues, which are able to decrease the intracellular level of Bcl-2 protein in leukemia cells, 2d makes them potential leads for development as new anticancer agents (Figure 1). However, most biological studies of indanone and its congeners have concentrated on plant models. Consequently, relatively little is known about the potential benefits of these molecules to human health. Thus, optically active indanone analogues, particularly spiroindanone derivatives, have emerged as important synthetic targets due to their diverse architectures and potential medicinal utility. In 2008, the groups of Yavari and Nair independently employed quinoline, dialkyl acetylenedicarboxylates and 1,3-indanedione to access spirocyclic molecules comprising of indanone and tetrahydropyrrolo[1,2-a]quinoline. 3 In the same year, Li and co-workers described a tandem Knoevenagel-1,3-dipolar cycloaddition cascade for a four-component synthesis of five-membered aza-spirocyclic indanediones. 4 Furthermore, Marini's group 5 reported an enantioselective one-pot synthesis of spiroindanones bearing an all-carbon chiral center at the C2 position by subjecting cyclic β-ketoesters and vinyl selenones to an organo-catalyzed Michael-cyclization sequence. Subsequently, Ramachary et al. presented the asymmetric synthesis of a spiroindane-1,3-dione skeleton incorporated with cyclohexane through a reflexive Michael reaction. 6 Although most efficient methods available in the literature have focused on the synthesis of diversely structured spiroindanones bearing an all-carbon ring or nitrogen heterocycle at the C2 position, the enantioselective preparation of the corresponding oxa-spirocyclic indanones remains underdeveloped. 7 Figure 1 Selected examples of biologically active indanonesThe development of multicomponent organocatalytic tandem reactions for introducing multi-chiral centers has been hotl...

show abstract

“…[11][12][13] Also, Jørgensen and Juhl developed the enantioselective inverse-electron-demand HDA reaction with an enamine generated in situ from an aldehyde and chiral amine with enones under organocatalysis. [14][15][16][17][18] As part of our program to engineer novel asymmetric assembly reactions that proceed in environmentally-sound conditions under amine-catalysis, 8,[19][20][21][22][23][24][25][26][27] we sought to extend the use of chiral organo-amines as catalysts for asymmetric HDA reactions.…”

Section: Introductionmentioning

confidence: 99%

Direct organocatalytic Wittig/Hetero-Diels-Alder reactions in one-pot: synthesis of highly-substituted tetrahydropyranones

Ramachary¹,

Mondal²,

Jain³

2015

Arkivoc

Self Cite

View full text Add to dashboard Cite

A practical and environmentally friendly organocatalytic one-pot strategy designed to furnish the hetero-Diels-Alder products was shown to be effective in the preparation of disubstituted tetrahydropyranones in a highly selective manner. (S)-1-(2-pyrrolidinylmethyl)pyrrolidine catalyzed an asymmetric assembly reaction involving a hetero-Diels-Alder reaction between alkylidene-and arylidene-acetones generated in situ from Wittig reactions with diethyl ketomalonate to furnish the substituted tetrahydropyranones in moderate to very good yields with moderate enantioselectivity.

show abstract

Dienamine Catalysis: An Emerging Technology in Organic Synthesis

Cited by 241 publications

References 117 publications

The ever-expanding role of asymmetric covalent organocatalysis in scalable, natural product synthesis

The ever-expanding role of asymmetric covalent organocatalysis in scalable, natural product synthesis

Asymmetric Synthesis of Oxa-spirocyclic Indanones with Structural Complexity via an Organocatalytic Michael–Henry–Acetalization Cascade

Direct organocatalytic Wittig/Hetero-Diels-Alder reactions in one-pot: synthesis of highly-substituted tetrahydropyranones

Contact Info

Product

Resources

About

Dienamine Catalysis: An Emerging Technology in Organic Synthesis

Cited by 241 publications

References 117 publications

The ever-expanding role of asymmetric covalent organocatalysis in scalable, natural product synthesis

The ever-expanding role of asymmetric covalent organocatalysis in scalable, natural product synthesis

Asymmetric Synthesis of Oxa-spirocyclic Indanones with Structural Com­plexity via an Organocatalytic Michael–Henry–Acetalization Cascade

Direct organocatalytic Wittig/Hetero-Diels-Alder reactions in one-pot: synthesis of highly-substituted tetrahydropyranones

Contact Info

Product

Resources

About

Asymmetric Synthesis of Oxa-spirocyclic Indanones with Structural Complexity via an Organocatalytic Michael–Henry–Acetalization Cascade