- Nickel-Catalyzed Reduction of Secondary and Tertiary Amides
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The nickel-catalyzed reduction of secondary and tertiary amides to give amine products is reported. The transformation is tolerant of extensive variation with respect to the amide substrate, proceeds in the presence of esters and epimerizable stereocenters, and can be used to achieve the reduction of lactams. Moreover, this methodology provides a simple tactic for accessing medicinally relevant α-deuterated amines.
- Simmons, Bryan J.,Hoffmann, Marie,Hwang, Jaeyeon,Jackl, Moritz K.,Garg, Neil K.
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supporting information
p. 1910 - 1913
(2017/04/11)
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- Direct N-alkylation of amines with alcohols using AlCl3 as a Lewis acid
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A substitution reaction of amines with alcohols for N-alkylated amines has been developed using inexpensive AlCl3 without any ligand or additive. Either aromatic or aliphatic amines and primary or secondary alcohols perform the AlCl3-mediated reaction smoothly to afford various N-alkylated amines in satisfactory yields.
- Li, Ya-Qiong,Chen, Yun-Bin,Huang, Zhi-Zhen
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p. 1540 - 1544
(2015/01/09)
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- One-pot anti-markovnikov hydroamination of unactivated alkenes by hydrozirconation and amination
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A one-pot anti-Markovnikov hydroamination of alkenes is reported. The synthesis of primary and secondary amines from unactivated olefins was accomplished in the presence of a variety of functional groups. Hydrozirconation, followed by amination with nitrogen electrophiles, provides exclusive anti-Markovnikov selectivity. Most products are isolated in high yields without the use of column chromatography.
- Strom, Alexandra E.,Hartwig, John F.
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p. 8909 - 8914
(2013/09/24)
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- Cesium effect: High chemoselectivity in direct N-alkylation of amines
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A novel method for the mono-N-alkylation of primary amines, diamines, and polyamines was developed using cesium bases in order to prepare secondary amines efficiently. A cesium base not only promoted alkylation of primary amines but also suppressed overalkylations of the produced secondary amines. Various amines, alkyl bromides, and alkyl sulfonates were examined, and the results demonstrated this methodology was highly chemoselective to favor mono-N-alkylation over dialkylation. In particular, use of either sterically demanding substrates or amino acid derivatives afforded the secondary amines exclusively, offering wide applications in peptidomimetic syntheses.
- Salvatore, Ralph Nicholas,Nagle, Advait S.,Kyung, Woon Jung
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p. 674 - 683
(2007/10/03)
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- Competing Hydride Transfer and Ene Reactions in the Aminoalkylation of 1-Alkenes with N,N-Dimethylmethyleniminium Ions. A Literature Correction
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A literature report that N,N-dimethylmethyleniminium ion (2) reacts with propylene and styrene to form unsaturated tertiary amines is shown to be incorrect.The major products are the secondary amines 1-(methylamino)butane and 1-(methylamino)-3-phenylpropane in which N-demethylation has occurred along with the saturation of the alkene.Analogous major products are formed with 1-butene, 1-hexene, 1-octene, 1-dodecene, 1-tetradecene, p-methylstyrene, and m-nitrostyrene as substrates.When the substrates are isobutylene, 2-ethyl-1-hexene, α-methylstyrene, and p-methoxystyrene, the major products are tertiary amines, but the secondary amines are also formed in smaller yields.The small yields of tertiary amines obtained in the cases of styrene and p-methylstyrene were increased by going from solvent acetic acid to acetonitrile and by increasing the branching of the alkyl groups on nitrogen.The internal olefins 5-decene and cyclohexene were far less reactive, giving only 3-4percent of amine products that were mainly tertiary in the former case and secondary in the latter.It is concluded that tertiary amine products are favored by an alkene structure and a solvent that favors the formation of a stable carbenium ion intermediate or a transition state with substantial carbenium ion character upon electrophilic attack of the iminium ion on the alkene.The secondary amine products are favored when a carbenium ion is of low stability and when the β-carbon atom of the olefin and/or the alkyl group attached to nitrogen is sterically unhindered; such hindrance decreases the rate of hydride ion transfer that is believed to occur in the production of secondary amines.
- Cohen, Theodore,Onopchenko, Anatoli
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p. 4531 - 4537
(2007/10/02)
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