First stereospecific total synthesis of (−)-affinisine oxindole as well as facile entry into the C(7)-diastereomeric chitosenine stereochemistry

Fonseca, German O.; Wang, Zhijian; Namjoshi, Ojas A.; Deschamps, Jeffrey R.; Cook, James M.

doi:10.1016/j.tetlet.2014.11.036

Cited by 23 publications

(22 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[17] The 1 H NMR (see SI Table 1) and 13 C NMR (see SI Table 2) spectral data, as well as the IR spectrum (dry film on KBr) 3375, 1711 cm− 1 [literature [16] IR (dry film) 3384, 1712 cm− 1 were in excellent agreement with the natural product. [16–17] In addition, the physical properties including the optical rotation [α] 23 D = −66° ( c 0.3, CHCl 3 ) [literature [16] [α] 23 D = −70° ( c 0.06, CHCl 3 )]; and HRMS were in excellent agreement with those published by Kam et al . [16–17] …”

Section: Resultsmentioning

confidence: 93%

“…The enantiospecific synthesis of alstonisine [2d] and affinisine oxindole [17] promoted further interest in the synthesis of other spiro oxindole alkaloids diastereomeric at the spiro juncture at C-7 via this strategy of internal asymmetric induction. Interestingly, Yu et al .…”

Section: Resultsmentioning

confidence: 99%

“…[23] The final steps in the first total synthesis of (−)-affinisine oxindole have been reported. [17] …”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Concise Total Synthesis of (−)‐Affinisine Oxindole, (+)‐Isoalstonisine, (+)‐Alstofoline, (−)‐Macrogentine, (+)‐N_a‐Demethylalstonisine, (−)‐Alstonoxine A, and (+)‐Alstonisine

Stephen

Rahman

Tiruveedhula

et al. 2017

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

A highly enantio- and diastereoselective strategy to access any member of the sarpagine/macroline family of oxindole alkaloids via internal asymmetric induction was developed from readily available D-(+)-tryptophan. At the center of this approach was the diastereospecific generation of the spiro[pyrrolidine-3,3’-oxindole] moiety at an early stage via a tert-butyl hypochlorite-promoted oxidative rearrangement of a chiral tetrahydro-β-carboline derivative. This key branching point determined the spatial configuration at the C-7 spiro center to be entirely 7R or 7S. Other key stereospecific processes were the asymmetric Pictet-Spengler reaction and Dieckmann cyclization, which were scalable to the 600 gram and 150 gram levels, respectively. Execution of this approach resulted in first enantiospecific total synthesis of (+)-isoalstonisine and (−)-macrogentine from the chitosenine series (7R), as well as (+)-alstonisine, (+)-alstofoline, (−)-alstonoxine A and (+)-Na-demethylalstonisine from the alstonisine series (7S).

show abstract

Section: Resultsmentioning

confidence: 93%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Concise Total Synthesis of (−)‐Affinisine Oxindole, (+)‐Isoalstonisine, (+)‐Alstofoline, (−)‐Macrogentine, (+)‐N_a‐Demethylalstonisine, (−)‐Alstonoxine A, and (+)‐Alstonisine

Stephen

Rahman

Tiruveedhula

et al. 2017

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

show abstract

“…The key step was an asymmetric Pictet-Spengler reaction carried out under Cook's conditions on a 300-gram scale [18], followed by diastereospecific oxidative-rearrangement of the tetrahydro-β-carboline to a spiroxindole (Scheme 4). The most interesting feature of this methodology was that the presence or absence of the N b -benzyl protecting group permitted access into either the chitosenine series or the alstonisine series [30]. feature of this methodology was that the presence or absence of the Nb-benzyl protecting group permitted access into either the chitosenine series or the alstonisine series [30].…”

Section: Starting From Tryptophan Derivativesmentioning

confidence: 99%

“…The most interesting feature of this methodology was that the presence or absence of the N b -benzyl protecting group permitted access into either the chitosenine series or the alstonisine series [30]. feature of this methodology was that the presence or absence of the Nb-benzyl protecting group permitted access into either the chitosenine series or the alstonisine series [30]. If Cook developed and studied the reaction condition for the "thermodynamic control", the reaction conditions for "kinetic control" were developed by Bailey.…”

Section: Starting From Tryptophan Derivativesmentioning

confidence: 99%

The Chiral Pool in the Pictet–Spengler Reaction for the Synthesis of β-Carbolines

Dalpozzo

2016

Molecules

View full text Add to dashboard Cite

Abstract:The Pictet-Spengler reaction (PSR) is the reaction of a β-arylethylamine with an aldehyde or ketone, followed by ring closure to give an aza-heterocycle. When the β-arylethylamine is tryptamine, the product is a β-carboline, a widespread skeleton in natural alkaloids. In the natural occurrence, these compounds are generally enantiopure, thus the asymmetric synthesis of these compounds have been attracting the interest of organic chemists. This review aims to give an overview of the asymmetric PSR, in which the chirality arises from optically pure amines or carbonyl compounds both from natural sources and from asymmetric syntheses to assemble the reaction partners.

show abstract

Phosphine‐mediated Highly Enantioselective Spirocyclization with Ketimines as Substrates

et al. 2016

View full text Add to dashboard Cite

Phosphine-catalyzed enantioselective annulation reactions involving ketimines are ad aunting synthetic challenge owingt ot he intrinsic low reactivity of ketimine substrates.Ah ighly enantioselective [3+ +2] cycloaddition reaction that makes use of isatin-derived ketimines as reaction partners was developed. Notably,b oth simple and g-substituted allenoates could be utilized,and various 3,2'-pyrrolidinyl spirooxindoles with at etrasubstituted stereocenter were obtained in excellent yields and with nearly perfect enantioselectivity (> 98 %eei nall cases).The ubiquity of spirocyclicf rameworks in natural products has long been af actor in galvanizing organic chemists to explore their preparation through the construction of carbocyclic and heterocyclic precursors.A mong established strategies,p hosphine-triggered annulation reactions have proven to be an efficient and versatile approach ever since the pioneering discovery of phosphine-catalyzed [3+ +2] cyclization by Lu and co-workers.[1] Nitrogen-containing ring systems are prevalent molecular architectures that are widely found in natural products and are extremely valuable as synthetic intermediates.Phosphine-catalyzed allene-imine annulation [2] is one of the most powerful methods for constructing such motifs,a nd has been widely employed in numerous syntheses of natural products and bioactive molecules. [3] In the vast majority of reported examples,aldehydederived aldimines are the electrophilic reaction partners utilized in these reactions.K etimines,o nt he other hand, are seldom used. Theu npopularity of ketimines in phosphine catalysis is likely due to their intrinsic low reactivity,s teric bulkiness,a nd the associated difficulty with stereochemical control. There are only two reports to date in which ketimines are employed for phosphine catalysis in anon-stereoselective manner, [4] and only one enantioselective example by Sasai and co-workers,which describes the use of cyclic ketimines in [4+ +2] annulation with allenoates.[5] Notably,t he cyclic ketimines utilized by Sasai et al. were rather special and the reaction suffered from arelatively narrow substrate scope.As part of our continued interests in phosphine catalysis, [6] we became interested in developing an efficient strategy for the use of ketimine substrates in common phosphine-mediated annulation reactions for the construction of molecular structures of biological significance (Scheme 1).Spirooxindoles are prominent structural motifs that are often found in natural products.A mong different spirooxindole cores,t he pyrrolidinyl spirooxindole frameworks represent av ery important class owing to their excellent bioactivity profiles.Most of the current research efforts have been focused on the synthesis of 3,3'-pyrrolidinyl spirooxindoles, [7] however, 3,2'-pyrrolidinyl spirooxindoles are also undeniably important and display ab road spectrum of biological activities [8] (Scheme 2). There are only ah andful of reports describing the synthesis of 3,2'-pyrrolidinyl scaffolds, [9] and these...

show abstract

First stereospecific total synthesis of (−)-affinisine oxindole as well as facile entry into the C(7)-diastereomeric chitosenine stereochemistry

Cited by 23 publications

References 38 publications

Concise Total Synthesis of (−)‐Affinisine Oxindole, (+)‐Isoalstonisine, (+)‐Alstofoline, (−)‐Macrogentine, (+)‐N_a‐Demethylalstonisine, (−)‐Alstonoxine A, and (+)‐Alstonisine

Concise Total Synthesis of (−)‐Affinisine Oxindole, (+)‐Isoalstonisine, (+)‐Alstofoline, (−)‐Macrogentine, (+)‐N_a‐Demethylalstonisine, (−)‐Alstonoxine A, and (+)‐Alstonisine

The Chiral Pool in the Pictet–Spengler Reaction for the Synthesis of β-Carbolines

Phosphine‐mediated Highly Enantioselective Spirocyclization with Ketimines as Substrates

Contact Info

Product

Resources

About

First stereospecific total synthesis of (−)-affinisine oxindole as well as facile entry into the C(7)-diastereomeric chitosenine stereochemistry

Cited by 23 publications

References 38 publications

Concise Total Synthesis of (−)‐Affinisine Oxindole, (+)‐Isoalstonisine, (+)‐Alstofoline, (−)‐Macrogentine, (+)‐Na‐Demethylalstonisine, (−)‐Alstonoxine A, and (+)‐Alstonisine

Concise Total Synthesis of (−)‐Affinisine Oxindole, (+)‐Isoalstonisine, (+)‐Alstofoline, (−)‐Macrogentine, (+)‐Na‐Demethylalstonisine, (−)‐Alstonoxine A, and (+)‐Alstonisine

The Chiral Pool in the Pictet–Spengler Reaction for the Synthesis of β-Carbolines

Phosphine‐mediated Highly Enantioselective Spirocyclization with Ketimines as Substrates

Contact Info

Product

Resources

About

Concise Total Synthesis of (−)‐Affinisine Oxindole, (+)‐Isoalstonisine, (+)‐Alstofoline, (−)‐Macrogentine, (+)‐N_a‐Demethylalstonisine, (−)‐Alstonoxine A, and (+)‐Alstonisine

Concise Total Synthesis of (−)‐Affinisine Oxindole, (+)‐Isoalstonisine, (+)‐Alstofoline, (−)‐Macrogentine, (+)‐N_a‐Demethylalstonisine, (−)‐Alstonoxine A, and (+)‐Alstonisine