Steric limits in the reactions of amines with in situ generted .alpha.-lactams. The synthesis of extremely sterically hindered tertiary amines

1993 ◽  
Vol 58 (6) ◽  
pp. 1604-1606 ◽  
Author(s):  
Frank S. Guziec ◽  
Felix F. Torres
Keyword(s):  
Tertiary Amines ◽  
Sterically Hindered

Nickel-Catalyzed Regioselective Hydroalkylation of 1,3-Dienes with Hydrazones

2019 ◽  
Author(s):  
Leiyang Lv ◽  
Dianhu Zhu ◽  
Zihang Qiu ◽  
Jianbin Li ◽  
Chao-Jun Li
Keyword(s):  
Catalytic Method ◽  
Unsaturated Hydrocarbons ◽  
Carbon Nucleophiles ◽  
Aryl Aldehydes ◽  
Aldehydes And Ketones ◽  
Sterically Hindered

Hydroalkylation of unsaturated hydrocarbons with unstablized carbon nucleophiles is difficult and remains a major challenge. The disclosed examples so far mainly focused on the involvement of heteroatom and/or stabilized carbon nucleophiles as efficient reaction partners. Reported here is an unprecedented regioselective nickel-catalyzed hydroalkylation of 1,3-dienes with hydrazones, generated in situ from abundant aryl aldehydes and ketones and acted as both the sources of unstabilized carbanions and hydride. With this strategy, both terminal and sterically hindered internal dienes are hydroalkylated efficiently in a highly selective manner, thus providing a novel and reliable catalytic method to construct challenging C(sp3)-C(sp3) bonds.

Direct oxidative cyanation of tertiary amines promoted by in situ generated hypervalent iodine(III)-CN intermediate

2015 ◽  
Vol 56 (41) ◽  
pp. 5628-5631 ◽  
Author(s):  
Hang Shen ◽  
Xiaohui Zhang ◽  
Qing Liu ◽  
Jing Pan ◽  
Wen Hu ◽  
...  
Keyword(s):  
Hypervalent Iodine ◽  
Tertiary Amines

Salts of ?-cyanoacrylic acid with sterically hindered tertiary amines

1992 ◽  
Vol 41 (1) ◽  
pp. 176-178 ◽  
Author(s):  
I. I. Kandror ◽  
B. D. Lavrukhin ◽  
M. A. Galkina ◽  
Yu. G. Gololobov
Keyword(s):  
Tertiary Amines ◽  
Cyanoacrylic Acid ◽  
Sterically Hindered

scholarly journals CO2 Absorption into Aqueous Amine Blends containing Benzylamine (BZA), Monoethanolamine (MEA), and Sterically Hindered/Tertiary Amines

2014 ◽  
Vol 63 ◽  
pp. 1835-1841 ◽  
Author(s):  
William Conway ◽  
Yaser Beyad ◽  
Paul Feron ◽  
Gilles Richner ◽  
Graeme Puxty
Keyword(s):  
Co2 Absorption ◽  
Tertiary Amines ◽  
Sterically Hindered

scholarly journals Preparation and in situ use of unstable N-alkyl a-diazo-g-butyrolactams in RhII-catalyzed X-H insertion reactions

2020 ◽  
Author(s):  
Maria Eremeyeva ◽  
Daniil Zhukovsky ◽  
Dmitry Dar'in ◽  
Mikhail Krasavin
Keyword(s):  
Aromatic Amines ◽  
Aliphatic Amines ◽  
Insertion Reactions ◽  
Sterically Hindered

N-Alkyl a-diazo-g-butyrolactams previously found to be unstable and undergo unproductive dimerization to bis-hydrazones, were successfully converted immediately to various X-H insertion products with alcohols, aromatic amines and thiols via an in situ RhII-catalyzed reaction. With aliphatic amines or unreactive, sterically hindered anilines, the reaction tends to yield enamine adducts.

scholarly journals RuO4-mediated oxidation of N-benzylated tertiary amines. 3. Behavior of 1,4-dibenzylpiperazine and its oxygenated derivatives

2006 ◽  
Vol 4 (4) ◽  
pp. 674-694 ◽  
Author(s):  
Horia Petride ◽  
Constantin Drăghici ◽  
Cristina Florea ◽  
Aurica Petride
Keyword(s):  
Benzoic Acid ◽  
Oxidation Reaction ◽  
Oxidation Mechanism ◽  
Tertiary Amines ◽  
Reaction Conditions ◽  
Iminium Cations ◽  
Work Up ◽  
Hydrolysis Of ◽  
Mediated Oxidation

Abstract1,4-Dibenzylpiperazine (1),-2-piperazinone (7),-2,6-piperazinedione (9), and 1-benzoyl-4-benzylpiperazine (30) were oxidized by RuO4 (generated in situ) by attack at their endocyclic and exocyclic (i.e., benzylic) aminic N-α-C-H bonds to afford various oxygenated derivatives, including acyclic diformamides, benzaldehyde, and benzoic acid. The reaction outcome was complicated by (i) the hydrolysis of diformamides, occurred during the work-up, and (ii) the reaction of benzaldehyde with the hydrolysis-derived amines giving imidazolidines and/or Schiff bases. Benzoic acid resulted from benzaldehyde only. Compounds 7, 30, and 1-benzylpiperazine, but not 9, were transiently formed during the oxidation of 1. In the same reaction conditions, 1,4-dibenzyl-2,3-(or 2,5)-piperazinedione, 1,4-dibenzyl-2,3,6-piperazinetrione, 4-benzyol-1-benzyl-2-piperazinone, and 1,4-dibenzoylpiperazine were inert. The proposed oxidation mechanism involves the formation of endocyclic and exocyclic iminium cations, as well as of cyclic enamines. The latter intermediates probably result by base-induced deprotonation of the iminium cations, provided an N +−β-proton is available. In the case of 1, the cations were trapped with NaCN as the corresponding α-aminonitriles. The statistically corrected regioselectivity (endocyclic/exocyclic) of the RuO4-induced oxidation reaction of 1, 7, and 30 was 1.2–1.3.

ChemInform Abstract: Direct Oxidative Cyanation of Tertiary Amines Promoted by in situ Generated Hypervalent Iodine(III)-CN Intermediate.

ChemInform ◽  
2016 ◽  
Vol 47 (4) ◽  
pp. no-no
Author(s):  
Hang Shen ◽  
Xiaohui Zhang ◽  
Qing Liu ◽  
Jing Pan ◽  
Wen Hu ◽  
...  
Keyword(s):  
Hypervalent Iodine ◽  
Tertiary Amines

Copper-Catalyzed γ-Cyanation of Aza-Baylis–Hillman Adducts Using Trimethylsilyl Cyanide

Synlett ◽  
2015 ◽  
Vol 26 (08) ◽  
pp. 1026-1030 ◽  
Author(s):  
Lal Yadav ◽  
Arvind Yadav
Keyword(s):  
Nucleophilic Attack ◽  
Tertiary Amines ◽  
Butyl Hydroperoxide ◽  
Trimethylsilyl Cyanide ◽  
Tert Butyl ◽  
Ion Formation ◽  
Tert Butyl Hydroperoxide ◽  
Iminium Ion ◽  
In Situ Formation

A copper-catalyzed γ-cyanation of aza-Baylis–Hillman adducts via iminium ion formation adjacent to benzylic tertiary amines has been developed using tert-butyl hydroperoxide (TBHP) as the external oxidant. The protocol involves in situ formation of 4π-conjugated iminium ion intermediates that undergo nucleophilic attack by cyanide to provide valuable γ-cyanated α,β-unsaturated amines.

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