cas 2449-49-2, N,N-DIMETHYL-1-PHENYLETHYLAMINE

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Preparation method of N-alkylated derivative of primary amine compound
The invention relates to a preparation method of an N-alkylated derivative of a primary amine compound. The method comprises the following steps: uniformly mixing a primary amine compound, an alcohol compound and a catalyst in a reactor, and heating to react for a period of time to generate an N-alkylated substituted tertiary amine compound; wherein the catalyst is a copper-cobalt bimetallic catalyst, and the carrier of the catalyst is Al2O3. According to the method, alcohol is adopted as an alkylating reagent and is low in price and easy to obtain, a byproduct is water, no pollution is caused to the environment, and the overall reaction atom economy is high; the catalyst is simple in preparation method, low in cost, high in reaction activity and good in structural stability; meanwhile, by using the copper-cobalt bimetallic catalyst, the use of strong base additives can be avoided, and the requirement on reaction equipment is low; and the reaction post-treatment is convenient, and the catalyst can be recycled and is environment-friendly.
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Paragraph 0021; 0053

(2021/07/09)

N-Methylation of Amines with Methanol in the Presence of Carbonate Salt Catalyzed by a Metal-Ligand Bifunctional Ruthenium Catalyst [(p-cymene)Ru(2,2′-bpyO)(H2O)]
A ruthenium complex [(p-cymene)Ru(2,2′-bpyO)(H2O)] was found to be a general and efficient catalyst for the N-methylation of amines with methanol in the presence of carbonate salt. Moreover, a series of sensitive substituents, such as nitro, ester, cyano, and vinyl groups, were tolerated under present conditions. It was confirmed that OH units in the ligand are crucial for the catalytic activity. Notably, this research exhibited the potential of metal-ligand bifunctional ruthenium catalysts for the hydrogen autotransfer process.
Liu, Peng,Tung, Nguyen Thanh,Xu, Xiangchao,Yang, Jiazhi,Li, Feng
p. 2621 - 2631
(2021/02/27)

Remarkably Efficient Iridium Catalysts for Directed C(sp2)-H and C(sp3)-H Borylation of Diverse Classes of Substrates
Here we describe the discovery of a new class of C-H borylation catalysts and their use for regioselective C-H borylation of aromatic, heteroaromatic, and aliphatic systems. The new catalysts have Ir-C(thienyl) or Ir-C(furyl) anionic ligands instead of the diamine-type neutral chelating ligands used in the standard C-H borylation conditions. It is reported that the employment of these newly discovered catalysts show excellent reactivity and ortho-selectivity for diverse classes of aromatic substrates with high isolated yields. Moreover, the catalysts proved to be efficient for a wide number of aliphatic substrates for selective C(sp3)-H bond borylations. Heterocyclic molecules are selectively borylated using the inherently elevated reactivity of the C-H bonds. A number of late-stage C-H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)-H and C(sp3)-H borylations enabling the method more general. Preliminary mechanistic studies suggest that the active catalytic intermediate is the Ir(bis)boryl complex, and the attached ligand acts as bidentate ligand. Collectively, this study underlines the discovery of new class of C-H borylation catalysts that should find wide application in the context of C-H functionalization chemistry.
Chattopadhyay, Buddhadeb,Hassan, Mirja Md Mahamudul,Hoque, Md Emdadul
supporting information
p. 5022 - 5037
(2021/05/04)

Synthesis of: N -methylated amines from acyl azides using methanol
The transformation of acyl azide derivatives into N-methylamines was developed using methanol as the C1 source via the one-pot Curtius rearrangement and borrowing hydrogen methodology. Following this protocol, various functionalised N-methylated amines were synthesized using the (NNN)Ru(ii) complex from carboxylic acids via an acyl azide intermediate. Several kinetic studies and DFT calculations were carried out to support the mechanism and also to determine the role of the Ru(ii) complex and base in this transformation.
Chakrabarti, Kaushik,Dutta, Kuheli,Kundu, Sabuj
p. 5891 - 5896
(2020/08/21)

N-Methylation of Amines with Methanol in Aqueous Solution Catalyzed by a Water-Soluble Metal-Ligand Bifunctional Dinuclear Iridium Catalyst
The N-methylation of amines with methanol in aqueous solution was proposed and accomplished by using a water-soluble metal-ligand bifunctional dinuclear iridium catalyst. In the presence of [(Cp*IrCl)2(thbpym)][Cl]2 (1 mol %), a range of desirable products were obtained in high yields under environmentally benign conditions. Notably, this research exhibited the potential of transition metal-catalyzed activation of methanol as a C1 source for the construction of the C-N bond in aqueous solution.
Han, Xingyou,Li, Feng,Liu, Peng,Meng, Chong,Tung, Nguyen Thanh
p. 5815 - 5824
(2020/05/26)

Base-induced Sommelet–Hauser rearrangement of N-(α-(2-oxyethyl)branched)benzylic glycine ester-derived ammonium salts via a chelated intermediate
The base-induced Sommelet–Hauser (S–H) rearrangement of N-(α-branched)benzylic glycine ester-derived ammonium salts 1 was investigated. When the α-branched substituent was a simple alkyl, such as a methyl or butyl, desired S–H rearrangement product 2 was obtained in low yield with formation of the [1,2] Stevens rearranged 4 and Hofmann eliminated products 5 and 6. However, when the α-branched substituent had a 2-oxy moiety, such as 2-acetoxyethyl or 2-benzoyloxyethyl, the yields of 2 were improved. These results could be explained by formation of chelated intermediate C that stabilizes the carbanionic ylide, and the subsequent initial dearomative [2,3] sigmatropic rearrangement would be accelerated. The existence of C was supported by mechanistic experiments. This enhancement effect is not very strong or effective; however, it will expand the synthetic usefulness of ammonium ylide rearrangements.
Baba, Souya,Hirano, Kazuki,Tayama, Eiji
supporting information

(2020/03/13)

Cu2O-catalyzed C–S coupling of quaternary ammonium salts and sodium alkane-/arene-sulfinates
A new protocol for the synthesis of (enantioenriched) benzylic sulfones via the Cu2O-catalyzed C–S bond cross coupling of alkane-/arene-sulfinates and (enantioenriched) benzylic quaternary ammonium salts has been developed. The product benzylic sulfones were obtained in good to high yields (75–96%). Chiral arylmethyl sulfones with high enantiomeric excess (90–94% ee) were also synthesized in the presence of Cu2O and 1,1′-bis-(diphenylphosphino)ferrocene (dppf).
Chen, Hongyi,Huang, Youming,Zeng, Qingle,Zheng, Wenting
supporting information

(2020/08/28)

Mechanistic Studies on the Nickel-Catalyzed Cyclopropanation with Lithiomethyltrimethylammonium Triflate
We report here our mechanistic study of the previously published nickel-catalyzed cyclopropanation reaction using lithiomethyltrimethylammonium triflate as methylene donor. The cyclopropane yield is highly dependent on the olefin substrate and correlates well with the binding affinity of the olefin to Ni(0) as established elsewhere. On the basis of this observation, we developed a simplified mechanistic model that can explain several odd observations we found in our initial report. Most importantly, a binding equilibrium between the olefin substrate and phosphine ligand appears to govern the ratio between product formation and unproductive ylide decomposition in a side reaction.
Künzi, Stefan A.,Gershoni-Poranne, Renana,Chen, Peter
p. 1928 - 1938
(2019/05/21)

Method for synthesizing methylated aliphatic amine compound
The invention discloses a method for synthesizing a methylated aliphatic amine compound. A commercially available or easily synthesized aliphatic amine, adopted as a raw material, is subjected to a methylation reaction with methanol to obtain the methylated aliphatic amine compound. The reaction is performed in the presence of an iridium metal complex and under weak alkaline catalysis conditions,only a N,N-dimethylated product is produced without generation of a monomethyl product so that selectivity is high, produced byproduct is water only so that no harm to the environment is caused, and the atom economy of the reaction is high, and therefore, the method meets the requirements of green chemistry and has a broad development prospect.
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Paragraph 0047; 0048; 0049; 0050; 0051

(2019/03/26)

Methyl-Selective α-Oxygenation of Tertiary Amines to Formamides by Employing Copper/Moderately Hindered Nitroxyl Radical (DMN-AZADO or 1-Me-AZADO)
Methyl-selective α-oxygenation of tertiary amines is a highly attractive approach for synthesizing formamides while preserving the amine substrate skeletons. Therefore, the development of efficient catalysts that can advance regioselective α-oxygenation at the N-methyl positions using molecular oxygen (O2) as the terminal oxidant is an important subject. In this study, we successfully developed a highly regioselective and efficient aerobic methyl-selective α-oxygenation of tertiary amines by employing a Cu/nitroxyl radical catalyst system. The use of moderately hindered nitroxyl radicals, such as 1,5-dimethyl-9-azanoradamantane N-oxyl (DMN-AZADO) and 1-methyl-2-azaadamanane N-oxyl (1-Me-AZADO), was very important to promote the oxygenation effectively mainly because these N-oxyls have longer life-times than less hindered N-oxyls. Various types of tertiary N-methylamines were selectively converted to the corresponding formamides. A plausible reaction mechanism is also discussed on the basis of experimental evidence, together with DFT calculations. The high regioselectivity of this catalyst system stems from steric restriction of the amine-N-oxyl interactions.
Nakai, Satoru,Yatabe, Takafumi,Suzuki, Kosuke,Sasano, Yusuke,Iwabuchi, Yoshiharu,Hasegawa, Jun-ya,Mizuno, Noritaka,Yamaguchi, Kazuya
supporting information
p. 16651 - 16659
(2019/11/11)

Selective synthesis of mono- and di-methylated amines using methanol and sodium azide as C1 and N1 sources
A Ru(ii) complex mediated synthesis of various N,N-dimethyl and N-monomethyl amines from organic azides using methanol as a methylating agent is reported. This methodology was successfully applied for a one-pot reaction of bromide derivatives and sodium azide in methanol. Notably, by controlling the reaction time several N-monomethylated and N,N-dimethylated amines were synthesized selectively. The practical applicability of this tandem process was revealed by preparative scale reactions with different organic azides and synthesis of an anti-vertigo drug betahistine. Several kinetic experiments and DFT studies were carried out to understand the mechanism of this transformation.
Chakrabarti, Kaushik,Mishra, Anju,Panja, Dibyajyoti,Paul, Bhaskar,Kundu, Sabuj
supporting information
p. 3339 - 3345
(2018/07/29)

Diverse catalytic reactivity of a dearomatized PN3P?-nickel hydride pincer complex towards CO2 reduction
A dearomatized PN3P?-nickel hydride complex has been prepared using an oxidative addition process. The first nickel-catalyzed hydrosilylation of CO2 to methanol has been achieved, with unprecedented turnover numbers. Selective methylation and formylation of amines with CO2 were demonstrated by such a PN3P?-nickel hydride complex, highlighting its versatile functions in CO2 reduction.
Li, Huaifeng,Gon?alves, Théo P.,Zhao, Qianyi,Gong, Dirong,Lai, Zhiping,Wang, Zhixiang,Zheng, Junrong,Huang, Kuo-Wei
supporting information
p. 11395 - 11398
(2018/10/20)

Lewis Acid-Catalyzed Reductive Amination of Aldehydes and Ketones with N,N-Dimethylformamide as Dimethylamino Source, Reductant and Solvent
A practical zinc acetate dihydrate-catalyzed reductive amination of various carbonyl compounds with N,N-dimethylformamide (DMF) as dimethylamino (Me2N) source, reductant and solvent has been developed. This reaction shows broad substrate scope,
Yang, Luo,Lin, Jie,Kang, Lei,Zhou, Wang,Ma, Da-You
supporting information
p. 485 - 490
(2018/01/15)

Efficient and versatile catalytic systems for the n-methylation of primary amines with methanol catalyzed by n-heterocyclic carbene complexes of iridium
Efficient and versatile catalytic systems were developed for the N-methylation of both aliphatic and aromatic primary amines using methanol as the methylating agent. Iridium complexes bearing an Nheterocyclic carbene (NHC) ligand exhibited high catalytic performance for this type of transformation. For aliphatic amines, selective N,N-dimethylation was achieved at low temperatures (50-90 °C). For aromatic amines, selective N-monomethylation and selective N,N-dimethylation were accomplished by simply changing the reaction conditions (presence or absence of a base with an appropriate catalyst). These findings can be used to develop methods for synthesizing useful amine compounds having N-methyl or N,N-dimethyl moieties.
Toyooka, Genki,Tuji, Akiko,Fujita, Ken-Ichi
p. 4617 - 4626
(2019/02/01)

Tertiary amine synthesis: Via reductive coupling of amides with Grignard reagents
A new iridium catalyzed reductive coupling reaction of Grignard reagents and tertiary amides affording functionalised tertiary amine products via an efficient and technically-simple one-pot, two-stage experimental protocol, is reported. The reaction-which can be carried out on gram-scale using as little as 1 mol% Vaska's complex [IrCl(CO)(PPh3)2] and TMDS as the terminal reductant for the initial reductive activation step-tolerates a broad range of tertiary amides from (hetero)aromatic to aliphatic (branched, unbranched and formyl) and a wide variety of alkyl (linear, branched), vinyl, alkynyl and (hetero)aryl Grignard reagents. The new methodology has been applied directly to bioactive molecule synthesis and the high chemoselectivity of the reductive coupling of amide has been exploited in late stage functionalization of drug molecules. This reductive functionalisation of tertiary amides provides a new and practical solution to tertiary amine synthesis.
Xie, Lan-Gui,Dixon, Darren J.
p. 7492 - 7497
(2017/10/30)

N-Methylation of Amines with Methanol Catalyzed by a Cp?Ir Complex Bearing a Functional 2,2′-Bibenzimidazole Ligand
A new type of Cp?Ir complex bearing a functional 2,2′-bibenzimidazole ligand was designed, synthesized, and found to be a highly effective and general catalyst for the N-methylation of a variety of amines with methanol in the presence of a weak base (0.3 equiv of Cs2CO3).
Liang, Ran,Li, Shun,Wang, Rongzhou,Lu, Lei,Li, Feng
supporting information
p. 5790 - 5793
(2017/11/10)

Simple Metal-Free Direct Reductive Amination Using Hydrosilatrane to Form Secondary and Tertiary Amines
This work describes the use of cheap, safe, and easy-to-handle hydrosilatrane as the reductant in direct reductive amination reactions. This efficient method enables a facile, metal-free access to secondary and tertiary amines from a wide range of aldehydes and ketones, with the synthesis of tertiary amines requiring no additives at all. This reaction demonstrates excellent functional group tolerance, chemoselectivity, and scalability. (Figure presented.).
Varjosaari, Sami E.,Skrypai, Vladislav,Suating, Paolo,Hurley, Joseph J. M.,Lio, Ashley M. De,Gilbert, Thomas M.,Adler, Marc J.
supporting information
p. 1872 - 1878
(2017/06/09)

The kinetics and mechanism of the organo-iridium catalysed racemisation of amines
The dimeric iodo-iridium complex [IrCp?I2]2 (Cp? = pentamethylcyclopentadiene) is an efficient catalyst for the racemisation of secondary and tertiary amines at ambient and higher temperatures with a low catalyst loading. The racemisation occurs with pseudo-first-order kinetics and the corresponding four rate constants were obtained by monitoring the time dependence of the concentrations of the (R) and (S) enantiomers starting with either pure (R) or (S) and show a first-order dependence on catalyst concentration. Low temperature 1H NMR data is consistent with the formation of a 1 : 1 complex with the amine coordinated to the iridium and with both iodide anions still bound to the metal-ion, but at the higher temperatures used for kinetic studies binding is weak and so no saturation zero-order kinetics are observed. A cross-over experiment with isotopically labelled amines demonstrates the intermediate formation of an imine which can dissociate from the iridium complex. Replacing the iodides in the catalyst by other ligands or having an amide substituent in Cp? results in a much less effective catalysts for the racemisation of amines. The rate constants for a deuterated amine yield a significant primary kinetic isotope effect kH/kD = 3.24 indicating that hydride transfer is involved in the rate-limiting step.
Stirling, Matthew J.,Mwansa, Joseph M.,Sweeney, Gemma,Blacker, A. John,Page, Michael I.
p. 7092 - 7098
(2016/07/30)

Simple Amine-Directed Meta-Selective C-H Arylation via Pd/Norbornene Catalysis
Herein we report a highly meta-selective C-H arylation using simple tertiary amines as the directing group. This method takes advantage of Pd/norbornene catalysis, offering a distinct strategy to control the site selectivity. The reaction was promoted by commercially available AsPh3 as the ligand and a unique "acetate cocktail". Aryl iodides with an ortho electron-withdrawing group were employed as the coupling partner. A wide range of functional groups, including some heteroarenes, are tolerated under the reaction conditions. In addition, the amine directing group can be easily installed and transformed to other common versatile functional groups. We expect this C-H functionalization mode to have broad implications for developing other meta-selective transformations beyond this work.
Dong, Zhe,Wang, Jianchun,Dong, Guangbin
supporting information
p. 5887 - 5890
(2015/05/27)

Light-promoted N,N-dimethylation of amine and nitro compound with methanol catalyzed by Pd/TiO2 at room temperature
A series of TiO2 supported nano-Pd catalysts (Pd/TiO2) were prepared and used for the N,N-dimethylation of different amines and nitro compounds with methanol under UV irradiation at room temperature. A wide range of N,N-dimethyl amines were one-pot synthesized with up to 98% by applying aliphatic secondary amines, aromatic primary amines, aliphatic primary amines and aromatic nitro compounds as starting materials. It is noteworthy that up to 90% yield of 4-chloro-N,N-dimethylaniline was obtained by adjusting the Pd loadings on the TiO2 and the dehalogenation reaction was inhibited. Finally, a reaction mechanism is discussed, involving PhN = CH2 and PhNHCH3 as reaction intermediates.
Zhang, Lina,Zhang, Yan,Deng, Youquan,Shi, Feng
p. 14514 - 14521
(2015/03/05)

N-Methylation of Amines with Methanol at Room Temperature
N-Methylation of amines with methanol proceeds at room temperature in the presence of a silver-loaded titanium dioxide (Ag/TiO2) photocatalyst under UV-vis light irradiation. This method allows facile synthesis/isolation of N-methylamines bearing various functional groups including N-benzyl, N-allyl, N-Boc, hydroxyl, ether, acetal, carboxamide, formamide, and olefin groups. (Chemical Presented)
Tsarev, Vasily N.,Morioka, Yuna,Caner, Joaquim,Wang, Qing,Ushimaru, Richiro,Kudo, Akihiko,Naka, Hiroshi,Saito, Susumu
supporting information
p. 2530 - 2533
(2015/05/27)

Sequential one-pot reactions of thioformamides with organolithium and zinc reagents
Sequential one-pot reactions of thioformamides with organolithium and zinc reagents were carried out. As thioformamides, N,N-dimethylthioformamide and N-ethoxycarbonyl N′-thioformyl piperazine were used. A variety of organolithium reagents such as alkyl, aryl, and heteroaryllithiums were used to give the corresponding amines in moderate to high yields. The efficiency of the reaction was influenced by the substituents on the aromatic rings. Thienyllithium gave the product in good yield, whereas the reaction offuryllithium was less efficient. A similar reaction with lithium acetylides was not successful. As an alternative method, methyl iodide was added to the reaction mixture ofthioformamides and lithium silylacetylide to form S,N-acetals as intermediates, and to this were added organozinc reagents to lead to propargylamines. For organozinc reagents, dialkyl zincs and 3- ethoxycarbonylpropylzinc bromide were used. The former reagents showed high efficiency when combined with several organolithium reagents, but the latter gave the corresponding product only when lithium silylacetylide was used as an initial reagent. Copyright Taylor & Francis Group, LLC.
Murai, Toshiaki,Matsushita, Koji
scheme or table
p. 1094 - 1103
(2011/09/14)

Fast racemisation of chiral amines and alcohols by using cationic half-sandwich ruthena- and iridacycle catalysts
The lipase-catalysed resolution of alcohols and amines yields only 50% of the desired enantiopure product. However, addition of a racemisation catalyst leads to 100% yield in what is called a dynamic kinetic resolution (DKR). There is a need for new racemisation catalysts that are fast and compatible with the conditions of the enzymatic reaction. We show that cationic half-sandwich ruthena- and iridacycle complexes are highly active and efficient in the racemisation of chiral alcohols and amines. Upon activation with base, these complexes are able to selectively racemise alcohols, whereas the non-activated complexes are selective catalysts for the racemisation of amines. We have applied the iridacycles in the DKR of racemic β-chloroalcohols to produce chiral epoxides in a biphasic system in good yields and high ee (ee = enantiomeric excess).
Jerphagnon, Thomas,Gayet, Arnaud J.A.,Berthiol, Florian,Ritleng, Vincent,Mrsic, Natasa,Meetsma, Auke,Pfeffer, Michel,Minnaard, Adriaan J.,Feringa, Ben L.,De Vries, Johannes G.
scheme or table
p. 12780 - 12790
(2010/06/16)

Synthesis of tertiary sec-alkylamines by the addition of grignard reagents to N,N-dialkylformamides mediated by Ti(OiPr)4 and Me3SiCl
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
experimental part
p. 5107 - 5111
(2009/06/17)

Efficient and mild procedure for reductive methylation of amines using N-methylpiperidine zinc borohydride
A simple and efficient procedure for reductive methylation of primary and secondary amines using N-methylpiperidine zinc borohydride (ZBNMPP), giving tertiary amines, is described. The reaction is carried out in methanol at room temperature under neutral conditions. Copyright Taylor & Francis Group, LLC.
Alinezhad, Heshmatollah,Tajbakhsh, Mahmood,Zamani, Reza
p. 3609 - 3615
(2007/10/03)

Selective N-methylation of primary aliphatic amines with dimethyl carbonate in the presence of alkali cation exchanged Y-faujasites
The N-methylation of aliphatic amines [XC6H4(CH 2)nNH2; n=1, X=H (1a), o-MeO (1b), p-MeO (1c); n=2, X=H (2a), o-MeO (2b); 1d: PhCH(Me)NH2] with dimethyl carbonate (DMC) is efficiently catalysed by NaY faujasite: on condition that CO 2 (a co-product of the reaction) is carefully removed, N-methyl- and N,N-dimethyl-amines (RNHMe and RNMe2) are obtained in good overall yields (70-90%). Otherwise, in the presence of CO2, carbamates (RNHCO2Me) form competitively to a large extent. The reaction probably proceeds through a BAl2 displacement of the amine on DMC.
Selva, Maurizio,Tundo, Pietro
p. 8139 - 8142
(2007/10/03)

A new phase transfer catalyst and its applications in organic transformations
A new quaternary ammonium bromide salt has been used for the first time in phase transfer catalysis (PTC) reactions such as oxidation of alcohols to carbonyl compounds, alkylation and esterification reactions. Improved yields and reduced reaction times have been achieved by this procedure.
Reddy, Ch. Venkateshwar,Mahesh,Raju,Reddy, V.V. Narayana
p. 2797 - 2802
(2007/10/03)

Lewis acid-catalyzed reductive amination of carbonyl compounds with aminohydrosilanes
The TiCl4-catalyzed reaction of aromatic carbonyl compounds with (dialkylamino)dimethylsilanes gave tertiary amines in moderate to high yields. The reductive amination of aliphatic aldehydes was effectively catalyzed by ZnI2. Methyl
Miura,Ootsuka,Suda,Nishikori,Hosomi
p. 1617 - 1619
(2007/10/03)

A high throughput synthesis of N,N-dimethyl tertiary amines
N,N-dimethyl tertiary amines are obtained in high yields by titanium(IV) isopropoxide mediated reductive amination of carbonyl compounds with a commercially available methanol solution of dimethylamine.
Bhattacharyya, Sukanta
p. 2001 - 2008
(2007/10/03)

Gas-phase selective N-alkylation of amines with alcohols over γ- alumina
Gas-phase conditions were successfully used for fine chemistry, in the N-alkylation of amines with alcohols as alkylating agents and γ-alumina as a catalyst. The method is also suitable for chiral compounds.
Valot, Frederic,Fache, Fabienne,Jacquot, Roland,Spagnol, Michel,Lemaire, Marc
p. 3689 - 3592
(2007/10/03)

Metallation of benzylic amines via amine-borane complexes
Formation of borane complexes of N,N-dimethylbenzylamine, N,N- dimethyl(1-naphthyl)methylamine, N,N-dimethyl(2-naphthyl)methylamine, N- methyltetrahydroisoquinoline and N-methylisoindoline facilitates regioselective metallation of these systems using BuLi, giving intermediate benzylic anions which react with a range of electrophiles to give products in good yield.
Ebden, Mark R.,Simpkins, Nigel S.,Fox, David N.A.
p. 12923 - 12952
(2007/10/03)

Mechanism of the Stevens rearrangement of ammonium ylides
Isomerization of trimethylammonium N-benzylide 2 failed to occur at room temperature in a non-basic medium (HMPA) or at -78°C in the presence of butyllithium in THF. However, N,N-dimethyl-1-phenylethylamine 4 (Stevens rearrangement product) was formed when the temperature of the latter reaction was raised to room temperature. The mechanism of the Stevens rearrangement is discussed.
Maeda, Yasuhiro,Sato, Yoshiro
p. 1491 - 1493
(2007/10/03)

Activation of Benzylic Amines Towards Regioselective Metallation by Borane Complex Formation
Formation of borane complexes of N,N-dimethylbenzylamine 4 and N-methyltetrahydroisoquinoline 1 facilitates regioselective metallation of these systems using BuLi, giving benzylic anions which react with a range of electrophiles.
Ebden, Mark R.,Simpkins, Nigel S.,Fox, David N. A.
p. 8697 - 8700
(2007/10/02)

The effect of the nature of the amine leaving group on the nature of the E2 transition state for the reaction of 1-phenylethylammonium ions with sodium ethoxide in ethanol
To investigate the effect of the leaving group on the elimination reaction of 1-phenylethylammonium ions with sodium ethoxide in ethanol at 60 deg C, the reaction of seven different quaternary ammonium salts and their β-deuterated analogues with trimethylamine, N-methylpiperidine, N-methyldiethylamine, triethylamine, N,N-dimethylbenzylamine, tripropylamine, and N,N-diethylbenzylamine as leaving groups has been studied.In all cases the elimination, which was shown to proceed via the concerted E2 process, was accompained by competing substitution reactions.Although a significant depedence of the rate of the elimination process on the nature of the leaving group was noted, there was not any linear correlation with the basicity of the amine leaving group.The primary hydrogen-deuterium kinetic isotope effect for the elimination process, (kH/kD)E, was found to increase initially with an increase of reaction rate, kHE, for substrates containing the leaving groups trimethylamine, N-methylpiperidine, N-methyldiethylamine, triethylamine, and N,N-dimethylbenzylamine; i.e., (kH/kD)E=5.03, 5.26, 5.40, 5.83, and 5.85, respectively.A further increase in rate, using substrates with tripropylamine and N,N-diethylbenzylamine as leaving groups resulted in a decrease of the magnitude of the hydrogen-deuterium isotope effect; i.e., (kH/kD)E= 5.42 and 4.67, respectively.It is concluded that steric effects mainly determine leaving group ability.As well, it is concluded that the leaving group ability of the amine determines the structure of the E2 transition state.For the reaction of the poorer leaving groups, trimethylamine, N-methylpiperidine, and N-methyldiethylamine, the proton is more than one-half transferred at the transition state while for reaction involving the two best leaving groups, tripropylamine and N,N-diethylbenzylamine, the Cβ-H bond is less than one-half broken at the transition state.The conclusions are considered in the light of the More O'Ferrall-Jencks potential energy surface diagram.Key words: elimination mechanism, transition state, isotope effects, leaving group, quaternary salts.
Smith, Peter James,Amin, Md.
p. 1457 - 1467
(2007/10/02)

STERIC CONSEQUENCE OF THE DIASTEREOSELECTIVE ADDITION OF CHIRAL LITHIUM 2-(1-DIMETHYLAMINOETHYL)PHENYL CUPRATES TO SOME ENONES
Conjugate addition of the mixed chiral species lithium ((S)-2-(1-dimethylaminoethyl)phenyl)(2-thienyl)cuprate to (E)-4-phenyl-3-buten-2-one, 2-cyclohexenone or to 2-cyclopentenone proceeds with high diastereoselectivity.The first two enones gave crystalline adducts directly, while the non-crystalline cyclopentenone adduct was converted into a crystalline methiodide.The crystal structures of the compounds have been determined from single-crystal X-ray diffractometer data in order to reveal the configurations at the new chiral centers.In all three cases the configuration at the new asymmetric centre is S. (S,S)-4-(2-(1-Dimethylaminoethyl)phenyl)-4-phenyl-2-butenone, C20H25NO, crystallizes in space group P21 with a 7.604(2), b 9.398(5), c 12.290(6) angstroem, β 92.30(3) deg and Z=2.Full-matrix least-squares refinement of 273 structural parameters gave R=0.066 for 1015 observed independent reflections. (S,S)-3-(2-(1-dimethylaminoethyl)phenyl)-2-cyclohexanone, C16H23NO crystallizes in space group P212121 with a 12.499(4), b 6.645(3), c 17.568(7) angstroem and Z=4.Full-matrix least-squares refinement of 142 structural parameters gave R=0.068 for 1507 observed independent reflections.(S,S)-1-(2-(3-Oxocyclopentyl)phenyl)ethyltrimethylammonium iodide, C16H24NOI, crystallizes in space group P41, with a 10.569(3), c 30.895(7) angstroem and Z=8; there are thus two crystallographically independent cations in the asymmetric unit.Full-matrix least-squares refinement of 342 structural parameters gave R=0.054 for 2119 observed independent reflections.The (S,S)-configuration observed in these adducts indicates that the conjugative addition gives the least crowded lithium enolate as the major product.
Andersson, Staffan,Jagner, Susan,Nilsson, Martin,Urso, Fabio
p. 257 - 268
(2007/10/02)

Base Catalysed Rearrangements involving Ylide Intermediates. Part 15. The Machanism of the Stevens Rearrangement
The Stevens rearrangement of acyl-stabilised ammonium ylides has been investigated with regard to stereoselectivity, intramolecularity and the formation of products in addition to the rearrangement product.A detailed study of the effects of reaction conditions upon the rearrangement of the ylide derived from the salt (13) has shown that the stereoselectivity (retention of the configuration of the chiral migrating group) and intramolecularity decrease as solvent viscosity decreases.The rearrangement of the salt (13) in water at 0 deg C is essentially intramolecular with virtually complete retention of the configuration of the migrating group.These results, together with the isolation of products that can be rationalised on the basis of random free-radical coupling, indicate that the rearrangement of acyl-stabilised ammonium ylides normally involves a radical pair mechanism.
Ollis, W. David,Rey, Max,Sutherland, Ian O.
p. 1009 - 1027
(2007/10/02)

A CHIRAL REAGENT IDUCING ASYMMETRY IN ELECTROPHILIC AMINATION REACTIONS
The chiral amination reagent (-)-1 was prepared from (-)-ephedrine, configurationally determined by X-ray structure analysis and reacted with carbon nucleophiles to yield the optically active amines 4a-d with up to 44percent ee.
Boche, Gernot,Schrott, Wolfgang
p. 5403 - 5406
(2007/10/02)

REACTION OF α-DIALKYLAMINOSTYRENES AND 2-(α-DIMETHYLAMINOVINYL)THIOPHENE WITH SULFENE AND THE READY THERMOLYSIS OF 3-PHENYL-3-DIMETHYLAMINOTHIETANE 1,1-DIOXIDE
A series of 3-aryl-3-dialkylaminothietane 1,1-dioxides were obtained by cycloaddition of sulfene to α-dialkylaminostyrenes and 2-(α-dimethylaminovinyl)thiophene in various solvents.It was shown that the initial process under the influence of electron impact and temperature is retro--dissociation of the four-membered ring.
Koikov, L. N.,Terent'ev, P. B.,Kulikov, N. S.
p. 960 - 964
(2007/10/02)

Enantioface-differentiating epoxidation of alkylidenemalononitriles with molecular oxygen, catalyzed by chiral tertiary amines
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Nanjo,Suzuki,Sekiya
p. 336 - 343
(2007/10/02)