A Novel Highly Selective Reduction of Tertiary Amides to Amines with Sodium Borohydride-Bis(2-bromoethyl)selenium Dibromide

Akabori, Sadatoshi; Takanohashi, Yoshinori

doi:10.1246/cl.1990.251

Cited by 21 publications

(6 citation statements)

References 6 publications

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“…The reduction of the amide bond by complex metal hydrides has significant synthetic importance for obtaining various amines. − Some amide compounds are able to react with amines, known as an acyl transfer or transamidation reaction (Scheme ). These processes represent very efficient transformations in synthetic organic chemistry towards selectively obtaining various amide structures from amino compounds.…”

Section: Introductionmentioning

confidence: 99%

A Quantitative Scale for the Extent of Conjugation of the Amide Bond. Amidity Percentage as a Chemical Driving Force

et al. 2007

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The amide bond may be considered as one of the most important chemical building blocks, playing an important role not only in living organisms but in organic chemistry as well. The exact description and precise quantification of the amide bond strength is difficult, requiring a particular type of theoretical investigation. The present paper suggests a novel, yet simple, method toward quantifying amide bond strength on a linear scale, defined as the "amidity scale". This is achieved using the computed enthalpy of hydrogenation (DeltaHH2) of the compound examined. In the present conceptual work, the DeltaHH2 value for dimethylacetamide is used to define perfect amidic character (amidity=+100%), while azaadamantane-2-on represents complete absence of amidic character (amidity=0%). The component DeltaHH2 values were computed at differing levels of theory, providing a computational and quasi-"method-independent" measure of amidity. A total of 29 well-known amides were examined to demonstrate the "scoring" accuracy of this methodology. For the compounds examined, a correlation has been made between the computed amidity percentage and their common COSNAR resonance energy values, proton affinities, and reactivity in a nucleophilic addition reaction. Selected chemical reactions were also studied. It has been shown that the change of the amidity value, during acyl transfer reactions, represents a thermodynamic driving force for the reaction.

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Section: Introductionmentioning

confidence: 99%

A Quantitative Scale for the Extent of Conjugation of the Amide Bond. Amidity Percentage as a Chemical Driving Force

et al. 2007

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“…Considering the structures of 4, 5 and 6, the four carbon atoms (the 1,2, I', 2' positions of the cyclohexane rings) which bond to the selenium or oxygen atoms of the aikoxy groups (7) may be asymmetric carbon atoms. However, the addition of selenium and alkoxy groups to the carbon-carbon double bond proceeded stereospecifically to give anti-addition products as described below.…”

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confidence: 99%

Selenium transfer reagent: one-step alkoxyselenation of cyclohexene with bis(2-bromoethyl)selenium dibromide

Takanohashi¹,

Tabata²,

Tanase³

et al. 1993

J. Chem. Soc., Perkin Trans. 1

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The reaction of bis(2-bromoethyl)selenium dibromide 1 with cyclohexene 2 in alcohol under reduced pressure proceeds smoothly t o give bis(2-alkoxycyclohexyl)selenium dibromide (R = M e 4, R = Et 5, R = Pr' 6) via 2-bromocyclohexyl-2'-bromoethylselenium dibromide 3 as an intermediate together with ethene. The diastereoisomers 4a and 5a (lR,2R,l'S,2'S) and 4b and 5b (1R,2R,ItR,2'R or IS,2S,l'S,2'S) were separated from 4 and/or 5. These isomers 4a/5a and 4b/5b were isolated as a meso and a racemic mixture, respectively. Although the addition product 6a (lR,2R,I'S,2'S) was only isolated from 6 in the meso form, the corresponding diastereoisomer 6b (1R,2R,ItR,2'R or IS,2S,l'S,2'S) was not detected. These results indicated that the Se and Br atoms in the cyclohexane ring of 3, and the Se and alkoxy groups in the cyclohexane rings of 4-6 were in the diequatorial position.* For details of the deposition scheme, see 'Instructions for Authors,'

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“…In 1990 Akabori and co‐authors reported a tertiary amide reduction with NaBH 4 in combination with bis(2‐bromoethyl)selenium dibromide. [ 198 ] This protocol can be applied only to the tertiary amides, while secondary and primary amides remain intact under these conditions. Following the procedure, Et 3 N was prepared in 70 % yield using 5 equivalents of NaBH 4 .…”

Section: Trialkylamines Synthesismentioning

confidence: 99%

Symmetrical Tertiary Amines: Applications and Synthetic Approaches

et al. 2020

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A Novel Highly Selective Reduction of Tertiary Amides to Amines with Sodium Borohydride-Bis(2-bromoethyl)selenium Dibromide

Abstract: Treatment of tertiary amides with sodium borohydride-bis(2-bromoethyl)selenium dibromide in THF gave the corresponding amines, although the similar reactions of secondary and primary amides could not proceeded.

Cited by 21 publications

References 6 publications

A Quantitative Scale for the Extent of Conjugation of the Amide Bond. Amidity Percentage as a Chemical Driving Force

A Quantitative Scale for the Extent of Conjugation of the Amide Bond. Amidity Percentage as a Chemical Driving Force

Selenium transfer reagent: one-step alkoxyselenation of cyclohexene with bis(2-bromoethyl)selenium dibromide

Symmetrical Tertiary Amines: Applications and Synthetic Approaches

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