Stereoselective Addition of a Lithium Anion of 1,1-Diphenyl-2-aza-pentadiene to Sulfinimines: Application to the Synthesis of (−)-Epiquinamide

Uphade, Manoj B.; Reddy, Arava Amaranadha; Khandare, Sopan P; Prasad, Kavirayani R.

doi:10.1021/acs.orglett.9b03507

Cited by 15 publications

(16 citation statements)

References 28 publications

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“…Therefore, we envisioned that use of an amino-substituted allyl reagent 12 in addition reactions with imine electrophiles would be a powerful strategy to prepare 1,2-diamines ( 13 ) with differential substitution patterns on nitrogen and containing an olefin motif for further functional group manipulations. Surprisingly, only a single example of such a strategy for the preparation of 1,2-diamines has been reported, which employs a lithiated derivative of 12 (M = Li) with chiral tert -butanesulfinimide derived aldimines affording products in moderate yields with mixtures of branched and linear allylation products . In contrast, amino-substituted allyl reagents 12 have been used in reactions employing carbonyl electrophiles to provide 1,2-aminoalcohols ( 16 ). − Recently, the Krische group and our own lab have developed reductive coupling , procedures for the catalytic generation of amino-substituted allyl reagents 12 and have studied their reactions with carbonyl electrophiles (Scheme C).…”

Section: Introductionmentioning

confidence: 99%

Access to Chiral Diamine Derivatives through Stereoselective Cu-Catalyzed Reductive Coupling of Imines and Allenamides

et al. 2021

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Chiral 1,2-diamino compounds are important building blocks in organic chemistry for biological applications and as asymmetric inducers in stereoselective synthesis that are challenging to prepare in a straightforward and stereoselective manner. Herein, we disclose a cost-effective and readily available Cu-catalyzed system for the reductive coupling of a chiral allenamide with N -alkyl substituted aldimines to access chiral 1,2-diamino synthons as single stereoisomers in high yields. The method shows broad reaction scope and high diastereoselectivity and can be easily scaled using standard Schlenk techniques. Mechanistic investigations by density functional theory calculations identified the mechanism and origin of stereoselectivity. In particular, the addition to the imine was shown to be reversible, which has implications toward development of catalyst-controlled stereoselective variants of the identified reductive coupling of imines and allenamides.

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Section: Introductionmentioning

confidence: 99%

Access to Chiral Diamine Derivatives through Stereoselective Cu-Catalyzed Reductive Coupling of Imines and Allenamides

et al. 2021

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“…Allylation of chiral imine (S S )-261 with concomitant cyclization led to piperidine 263 as a single diastereoisomer. Removal of diphenylmethylidene group and acylation of the resulting free amine provided compound 264, which after desulfinylation, N-allylation, ring-closing metathesis and catalytic hydrogenation produced the quinolizidine alkaloid (−)-epiquinamide (266), isolated from the skin of the Ecuadoran frog Epipedobates tricolor (Scheme 60) [159].…”

Section: Initial Stereocontrol By Allylation Of Sulfinyl Iminesmentioning

confidence: 99%

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

Mendes¹,

Costa²,

Yus³

et al. 2021

Beilstein J. Org. Chem.

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The synthesis of nitrogen-containing heterocycles, including natural alkaloids and other compounds presenting different types of biological activities have proved to be successful employing chiral sulfinyl imines derived from tert-butanesulfinamide. These imines are versatile chiral auxiliaries and have been extensively used as eletrophiles in a wide range of reactions. The electron-withdrawing sulfinyl group facilitates the nucleophilic addition of organometallic compounds to the iminic carbon with high diastereoisomeric excess and the free amines obtained after an easy removal of the tert-butanesulfinyl group can be transformed into enantioenriched nitrogen-containing heterocycles. The goal of this review is to the highlight enantioselective syntheses of heterocycles involving the use of chiral N-tert-butanesulfinyl imines as reaction intermediates, including the synthesis of several natural products. The synthesis of nitrogen-containing heterocycles in which the nitrogen atom is not provided by the chiral imine will not be considered in this review. The sections are organized according to the size of the heterocycles. The present work will comprehensively cover the most pertinent contributions to this research area from 2012 to 2020. We regret in advance that some contributions are excluded in order to maintain a concise format.

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“…The reaction of imines 16 with allylimine 24 in the presence of Bu n Li and TMEDA led to the formation of compounds 25 (Scheme 10). [21] In the case of R=Br(CH 2 ) 4 , the reaction gave a piperidine derivative, which after some transformation, led to (−)‐epiquinamide. The stereochemistry of the obtained products was explained through the model I .…”

Section: Organoalkaline Compoundsmentioning

confidence: 99%

Chiral N‐tert‐Butylsulfinyl Imines: New Discoveries

Foubelo

Yus

2020

The Chemical Record

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In this account the reactions of chiral N‐tert‐butylsulfinyl imines with organometallic reagents such as organoalkaline (lithium, sodium, potassium and cesium derivatives), organomagnesium, organozinc, organoboron, organoaluminium, organoindium and organosilicon compounds is comprehensively described. The reactivity in all cases is derived to synthetic applications in order to prepare interesting organic nitrogenated molecules, especially in the field of alkaloid compounds.

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Stereoselective Addition of a Lithium Anion of 1,1-Diphenyl-2-aza-pentadiene to Sulfinimines: Application to the Synthesis of (−)-Epiquinamide

Cited by 15 publications

References 28 publications

Access to Chiral Diamine Derivatives through Stereoselective Cu-Catalyzed Reductive Coupling of Imines and Allenamides

Access to Chiral Diamine Derivatives through Stereoselective Cu-Catalyzed Reductive Coupling of Imines and Allenamides

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

Chiral N‐tert‐Butylsulfinyl Imines: New Discoveries

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