- Mannich-like three-component synthesis of α-branched amines involving organozinc compounds: ReactIR monitoring and mechanistic aspects
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The infra-red spectroscopic in situ examination of the Mannich-like three-component reaction between organozinc reagents, amines and aldehydes is described, revealing that two distinct pathways are favored, depending on the nature of the starting amine. While reactions involving primary amines proceed via in situ-formed imines, reactions involving secondary amines rather imply a hemiaminal as the key intermediate species.
- Le Gall, Erwan,Sengmany, Stéphane,Hauréna, Caroline,Léonel, Eric,Martens, Thierry
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- A four-component reaction involving in situ generated organometallic reagents: Straightforward access to β-amino esters
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Four in one: A straightforward synthesis of β2,3-amino esters is described through a new zinc-mediated, cobalt-catalyzed four-component reaction between organic bromides, alkyl acrylates, amines, and aldehydes (see scheme). Synthesis involves a Mannich-related conjugate addition/aza-aldol domino sequence, allowing the formation of three single bonds in one step. A reaction mechanism, emphasizing the crucial role of zinc salts, is described. Copyright
- LeGall, Erwan,Leonel, Eric
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Read Online
- Atom-efficient transition-metal-free arylation ofN,O-acetals using diarylzinc reagents through Zn/Zn cooperativity
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Exploiting the cooperative action of Lewis acid Zn(C6F5)2with diarylzinc reagents, the efficient arylation ofN,O-acetals to access diarylmethylamines is reported. Reactions take place under mild reaction conditions without the need for transtion-metal catalysis. Mechanistic investigations have revealed that Zn(C6F5)2not only acts as a Lewis acid activator, but also enables the regeneration of nucleophilic ZnAr2species, allowing a limiting 50 mol% to be employed.
- Borys, Andryj M.,Gil-Negrete, Jose M.,Hevia, Eva
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supporting information
p. 8905 - 8908
(2021/09/10)
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- Metal-free iodine-promoted direct synthesis of unsymmetrical triarylmethanes
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A highly efficient strategy to synthesize completely unsymmetrical triarylmethanes promoted by iodine under metal-free conditions has been successfully developed. Three different aryl groups were introduced into triarylmethanes in a one-pot reaction from inexpensive and readily available salicylaldehydes, arylboronic acids and arenes via o-QM intermediates generated in situ, delivering a wide range of unsymmetrical triarylmethanes bearing various functional groups in good yields with excellent chemoselectivity.
- Gu, Ying-Chun,Huang, Jie,Wu, Run-Shi,Xu, Da-Zhen,Yang, Qi,Yu, Ya-Qin
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p. 5519 - 5525
(2020/04/17)
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- Skin
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PROBLEM TO BE SOLVED: To provide a skin care preparation suitable for a cosmetic (provided that quasi drugs are included) or the like, for detail, a skin care preparation having whitening effects, particularly preventive or improving effects against pigme
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Paragraph 0072
(2018/03/23)
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- Skin care
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PROBLEM TO BE SOLVED: To provide a skin care preparation suitable for preventing or ameliorating pigment deposition. SOLUTION: The skin care preparation comprises two compounds represented by general formula (1) [wherein R1is an aromatic group; R2is a hydrogen atom, alkyl or acyl; R3is a hydrogen atom or alkyl] and represented by general formula (2) [wherein R4is an aromatic group or hydrogen atom; R5and R6are each an aromatic group; R7and R8are mutually bonded to form a 2-8C nitrogen heterocyclic ring]. COPYRIGHT: (C)2013,JPOandINPIT
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Paragraph 0116-0117
(2020/10/19)
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- Skin care
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PROBLEM TO BE SOLVED: To provide a skin care preparation suitable for a cosmetic (provided that quasi drugs are included) or the like, for detail, a skin care preparation having whitening effects, particularly preventive or improving effects against pigme
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Paragraph 0071; 0073
(2017/10/05)
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- Copper(I)-catalyzed coupling reaction of aryl boronic acids with N,O-acetals and N,N-aminals under atmosphere leading to α-aryl glycine derivatives and diarylmethylamine derivatives
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We demonstrated a copper(I)-catalyzed coupling reaction of aryl boronic acids with N,O-acetals and N,N-aminals leading to the synthesis of α-aryl glycines and diarylmethylamines. Under an ambient atmosphere, this catalytic system could be applied to the activation of a C(sp3)-O bond of N,O-acetals with an ester and an aryl group, or without a coordinating substituent, as well as to a C(sp3)-N bond of N,N-aminals.
- Sakai, Norio,Hori, Hiroaki,Yoshida, Yoshihiro,Konakahara, Takeo,Ogiwara, Yohei
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p. 4722 - 4729
(2015/07/27)
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- Can one predict changes from SN1 to SN2 mechanisms?
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The reactions of substituted benzhydryl bromides Ar2CHBr with primary and secondary amines in DMSO yield benzhydryl amines Ar 2CHNRR′, benzophenones Ar2CdO, and benzhydrols Ar2CHOH. Kinetic investigations at 20°C revealed the rate law -d[Ar2CHBr]/dt = (k1 + k2[HNRR′])[Ar 2CHBr], where the amine independent term k1 gave rise to the formation of Ar2CdO and Ar2CHOH and the amine-dependent term k2[HNRR′] was responsible for the formation of Ar2CHNRR′. Clear evidence for concomitant S N1 and SN2 processes was obtained. While the rate constants of the SN1 reactions correlate with Hammett's σ+ constants (ρ = -3.22), the second-order rate constants k2 for the SN2 reactions are not correlated with the electron releasing abilities of the substituents, indicating that the transition states of the SN2 reactions do not merge with the transition states of the SN1 reactions. The correlation equation log k 20°C = s(E + N), where nucleophiles are characterized by N and s and electrophiles are characterized by E (J. Am. Chem. Soc. 2001, 123, 9500-9512), was used to calculate the lifetimes of benzhydrylium ions in the presence of amines and DMSO. The change from SN1 to SN2 mechanism occurred close to the point where the calculated rate constant for the collapse of the benzhydrylium ions with the amines just reaches the vibrational limit; that is, the concerted SN2 mechanism was only followed when it was enforced by the lifetime of the intermediate. The nucleophile-specific parameters N and s needed for this analysis were determined by studying the kinetics of the reactions of a variety of amines with amino-substituted benzhydrylium tetrafluoroborates (Ar2CH+BF4-) of known electrophilicity E in DMSO. Analogously, the rates of the reactions of laser flash photolytically generated benzhydrylium ions Ar2CH + with DMSO in acetonitrile were employed to determine the nucleophile-specific parameters N and s of DMSO, and it is reported that DMSO is a significantly stronger O-nucleophile than water and ordinary alcohols.
- Thanh, Binh Phan,Nolte, Christoph,Kobayashi, Shinjiro,Ofial, Armin R.,Mayr, Herbert
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supporting information; experimental part
p. 11392 - 11401
(2011/02/27)
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- Synthesis of tertiary sec-alkylamines by the addition of grignard reagents to N,N-dialkylformamides mediated by Ti(OiPr)4 and Me3SiCl
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A number of tertiary sec-alkylamines (22 examples, 29-80% yield) have been prepared according to a simple one-pot procedure by the addition of Grignard reagents to N,N-dialkylformamides in the presence of Ti(OiPr)4 and Me3SiCl. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Tomashenko, Olesya,Sokolov, Viktor,Tomashevskiy, Alexander,Buchholz, Herwig A.,Welz-Biermann, Urs,Chaplinski, Vladimir,De Meijere, Armin
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experimental part
p. 5107 - 5111
(2009/06/17)
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- One-step three-component coupling of aromatic organozinc reagents, secondary amines, and aromatic aldehydes into functionalized diarylmethylamines
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Numerous functionalized diarylmethylamines have been synthesized in high yield according to a one-step three-component coupling between an aromatic organozinc reagent, a secondary amine, and an aromatic aldehyde. Both organozinc species and aldehyde can bear a functional group and either aromatic or non-aromatic amines can be used in this versatile procedure.
- Le Gall, Erwan,Troupel, Michel,Nédélec, Jean-Yves
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p. 9953 - 9965
(2007/10/03)
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- Piperidine derivatives useful as CCR5 antagonists
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The use of CCR5 antagonists of the formula or a pharmaceutically acceptable salt thereof, wherein X is —C(R13)2—, —C(R13)(R19)—, —C(O)—, —O—, —NH—, —N(alkyl)—, R is optionally substituted phenyl, pyridyl, thiophenyl or naphthyl; R1is H, alkyl or alkenyl; R2is optionally substituted phenyl, phenylalkyl, heteroaryl or heteroarylalkyl, naphthyl, fluorenyl or diphenylmethyl; R3is optionally substituted phenyl, heteroaryl or naphthyl; R4is H, alkyl, fluoro-alkyl, cyclopropylmethyl, —CH2CH2OH, —CH2CH2—O-alkyl, —CH2C(O)—O-alkyl, —CH2C(O)NH2, —CH2C(O)—NHalkyl or —CH2C(O)—N(alkyl)2; R19is optionally substituted phenyl, heteroaryl or naphthyl, cycloalkyl, cycloalkylalkyl or alkoxyalkyl; and R5, R13, R14, R15and R16are hydrogen or alkyl for the treatment of HIV, solid organ transplant rejection, graft v. host disease, arthritis, rheumatoid arthritis, inflammatory bowel disease, atopic dermatitis, psoriasis, asthma, allergies or multiple sclerosis is disclosed, as well as novel compounds, pharmaceutical compositions comprising them, and the combination of CCR5 antagonists of the invention in combination with antiviral agents useful in the treatment of HIV or agents useful in the treatment of inflammatory diseases.
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- A single step reductive amination of carbonyl compounds with polymethylhydrosiloxane-Ti(O(i)Pr)4
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Highly chemoselective 'one pot' amination of carbonyl groups is achieved using polymethylhydrosiloxane (PMHS) as reductant and Ti(O(i)Pr)4 as activator. A comparative study with other activators such as AlCl3 and Pd-C was also studied.
- Chandrasekhar,Reddy,Ahmed
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p. 1655 - 1657
(2007/10/03)
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- A Novel Deselenation in the Reaction of Selenoamides with Organolithium Reagents
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The reaction of selenoamides with organolithium reagents proceeds in a carbophilic manner, and more interestingly, the presence of excess lithium reagents causes a novel deselenation reaction from the carbophilic adducts.
- Sekiguchi, Masahito,Ogawa, Akiya,Fujiwara, Shin-Ichi,Ryu, Ilhyong,Kambe, Nobuaki,Sonoda, Noboru
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p. 2053 - 2056
(2007/10/02)
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- Bis(acetylacetonato)copper (II)-catalysed Insertion of Diphenylcarbene into N-H Bonds of Piperidine and Diphenylamine
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The reaction of diphenyldiazomethan (I) with piperidine and diphenylamine in the presence of bis(acetylacetonato)copper (II) affords N-diphenylmethylpiperidine (IIIa) and N,N-diphenylbenzhydrylamine (IIIb), respectively.The insertion of diphenylcarbene, f
- Mehrotra, K. N.,Singh, G. S.
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p. 773 - 774
(2007/10/02)
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