38924-79-7

Upstream product

• 103-30-0 (E)-1,2-diphenyl-ethene 
• 99-99-0 1-methyl-4-nitrobenzene 
• 1539-57-7 diethyl 2,6-dimethyl-4-benzyl-1,4-dihydropyridine-3,5-dicarboxylate 
• 2272-45-9 benzal-p-toluidine 
• 106-49-0 p-toluidine 
• 100-51-6 benzyl alcohol 
• 501-65-5 diphenyl acetylene 

Relevant academic research and scientific papers

Remote sp3 C–H Amination of Alkenes with Nitroarenes

Direct installation of a functional group at remote, unfunctionalized sites in an alkyl chain is a synthetically valuable but rarely reported process. The remote relay hydroarylamination of distal and proximal olefins, and of olefin isomeric mixtures, has been achieved through NiH-catalyzed alkene isomerization and sequential reductive hydroarylamination with nitroarenes. This provides an attractive approach to the direct installation of a distal arylamino group within alkyl chains. The single-step conversion of simple olefins and nitro(hetero)arenes to value-added arylamines is a practical strategy for amine synthesis as well as the remote activation of sp3 C–H bonds. The value of this transformation is further supported by the regioconvergent arylamination of isomeric mixtures of olefins. Modern organic synthesis requires more efficient strategies, such as C–H functionalization, with which to construct complex molecules from readily available chemicals. Undirected functionalization of remote aliphatic C–H bonds is a synthetically valuable but largely unknown process. Synergistic combination of metal-catalyzed chainwalking (migration of a double bond along the hydrocarbon chain, a process involving repeated migratory insertions and β-hydride eliminations) and cross-coupling chemistry offers a general approach to the remote functionalization of easily accessed unsaturated hydrocarbon substrates. In this paper, we demonstrate that direct installation of a distal arylamino group can be achieved from two common feedstock chemicals (olefins and nitroarenes) via nickel hydride chemistry. It is anticipated that the strategy could inspire the development of other remote functionalizations with different regioselectivity as well as asymmetric transformations. Zhu and colleagues describe the remote hydroamination of alkenes with nitro(hetero)arenes through nickel-catalyzed alkene isomerization and sequential reductive relay hydroamination process. Using two common feedstock chemicals, olefins and nitroaromatics, in an operationally simple procedure, this attractive protocol provides efficient and practical access to a wide range of arylamines under mild conditions.

Radical alkylation of imines with 4-alkyl-1,4-dihydropyridines enabled by photoredox/br?nsted acid cocatalysis

Radical alkylation of imines with 4-alkyl-1,4-dihydropyridines cocatalyzed by iridium/ruthenium complex and Br?nsted acid under visible light irradiation has been achieved. Both aldimines and ketimines can undergo this transformation. Common functional groups, such as hydroxyl groups, ester, amide, ether, cyanide, and heterocycles, can be tolerated in this reaction. A variety of structurally diverse amines (57 examples) have been produced with up to 98% isolated yields using this method.

Palladium-catalyzed benzylic C-H benzylation via bis-benzylpalladium(II) complexes in water: An effective pathway for the direct construction of N-(1,2-diphenylethyl)anilines

A strategy for the N-benzylation/benzylic C-H benzylation cascade of anilines by the π-benzylpalladium system using a water-soluble palladium(0)/sodium diphenylphosphinobenzene-3-sulfonate (TPPMS) catalyst and benzyl alcohol in water has been developed. This tandem process is devised as a novel and efficient synthetic route for N-(1,2-diphenylethyl)anilines. Benzylic C-H activation of a mono-N-benzylated intermediate with a π-benzylpalladium(II) complex affords a bis-π-benzylated palladium(II) intermediate. The nucleophilic η1-σ-benzyl anion ligand attacks the electrophilic η3-π-benzyl ligand to give a dibenzylated product. The intermolecular competition between mono-N-benzylaniline and its monodeuterated form (monodeuterated at the benzylic group) with benzyl alcohol gave a KIE=4.6, suggesting that C-H bond cleavage was involved in the rate-determining step. Hammett studies on the rate constants of benzylation by various substituted anthranilic acids and mono-N-benzylanilines show a good correlation between the log(kX/kH) and the σ values of the respective substituents. From the slope, negative ρ values are obtained, suggesting that there is a build-up of positive charge in the transition state. The reaction of anilines with electron-donating and electron-withdrawing groups affords the corresponding N-(1,2-diphenylethyl)anilines in moderate to good yields (54-86%). Interestingly, the reaction of anthranilic acids proceeded smoothly to give only the corresponding dibenzylated products in good to excellent yields (70-87%). The carboxyl group of the anthranilic acids acts as a directing group in the benzylic C-H activation process.

An (Aminopyrimidinato)titanium catalyst for the hydroamination of alkynes and alkenes

A new (aminopyrimidinato)titanium complex has been synthesised from inexpensive and easily accessible 2-(tert-butylamino)pyrimidine and [Ti(NMe 2)4] and used as a catalyst for the intermolecular hydroamination of alkynes as well as the cyclization of aminoalkenes. The hydroamination reactions of 1-phenylpropyne and terminal arylalkynes deliver the corresponding anti-Markovnikov addition products with excellent yields and regioselectivities. A new (aminopyrimidinato)titanium complex has been synthesised from inexpensive 2-(tert-butylamino)pyrimidine and [Ti(NMe 2)4] and used as a catalyst for the intermolecular hydroamination of alkynes as well as the cyclization of aminoalkenes. The complex represents the first example of a catalyst for the hydroamination of alkynes that contains an aminoheteroaromatic ancillary ligand.

Zirconium-catalyzed intermolecular hydroamination of alkynes with primary amines

A simple catalyst system generated in situ by combination of 5 mol-% [Zr(NMe2)4] and 10 mol-% of a sulfonamide catalyzes the intermolecular hydroamination of alkynes with primary amines. At elevated temperatures, hydroamination is achieved with both internal and terminal alkynes as well as with sterically demanding and less demanding primary amines. In contrast, secondary amines do not react under identical conditions. Of the sulfonamide additives investigated, sterically demanding tosylamides such as N-(tert-butyl)-p-toluenesulfonamide give the best results. The regioselectivity of the addition of amine to unsymmetrically substituted internal as well as terminal alkynes is significantly influenced by the nature of the sulfonamide additive. In particular, the successful use of sterically less demanding primary amines such as n-hexyl-or benzylamine clearly indicates that the assumption that Zr catalysts generally form catalytically inactive bridging μ2-imido dimers or other unreactive intermediates in the presence of these amines is not correct. Intermolecular hydroamination reactions of alkynes with primary amines that are sterically less demanding than 2,6-dimethylaniline can be achieved with in situ generated zirconium catalysts. This finding is highly important for a better and more general understanding of the mechanism of group 4 metal-catalyzed hydroamination reactions. Copyright

Potassium hydroxide catalyzed addition of arylamines to styrenes

Potassium hydroxide is a competent and cheap catalyst for the intermolecular addition of arylamines to styrenes. The reactions are performed in nontoxic dimethyl sulfoxide and can be used for the large-scale synthesis of β-phenylethylamines. Georg Thieme Verlag Stuttgart - New York.

Titanium hydroamination catalysts bearing a 2-aminopyrrolinato spectator ligand: Monitoring the individual reaction steps

A series of new titanium half sandwich complexes, containing a 2-aminopyrrolinato ligand {NXylN}- as the ancillary ligand, have been prepared and are shown to be pre-catalysts for the hydroamination of alkynes. The coordination of {NXylN}- to titanium was achieved by reaction of [Cp*TiMe3] with the protioligand NXylNH giving [Cp*Ti(NXylN)(Me) 2] (1). Upon reaction of complex 1 with an excess of tert-butylamine, the imido complex [Cp*Ti(NXylN)(NtBu)(NH 2tBu)] (2) was formed. The latter provided the preparative entry to the synthesis of a range of N-aryl substituted imido complexes. Imido ligand exchange with 2,6-dimethylaniline, 2,4,6-trimethylaniline as well as 2,6-diisopropylaniline gave the corresponding arylimido complexes 3-5 in clean reactions. Reaction of the titanium imido complex [Cp*Ti(N XylN)(NtBu)(NH2tBu)] 2 with terminal arylacetylenes, such as phenylacetylene and tolylacetylene, led to C-H activation and the formation of alkynyl/amido complexes, whereas the arylimido complexes 3 and 5 cleanly underwent {2 + 2} cycloaddition, giving the azatitanacyclobutene derivatives. A single-crystal X-ray structure analysis of the azatitanacyclobutene [Cp*Ti(NXylN){κ2N(2, 6-C6H3Me2)CTolCH}] (11) provided the first crystallographically characterized Markovnikov cycloaddition product of an imidotitanium complex with a terminal alkyne. The mechanistic aspects of the hydromanination of alkynes with the new Ti half sandwich complexes were studied and established a reversible {2 + 2} cycloaddition step and the cleavage of the metallacyclic intermediate as the rate determining step in the catalytic cycle. The titanium half sandwich imido complexes were found to be active catalysts for the inter- and intramolecular hydroamination of a broad range of alkynes and ω-aminoalkynes.

Triazole-Au(I) complexes: A new class of catalysts with improved thermal stability and reactivity for intermolecular alkyne hydroamination

(Chemical Equation Presented) A series of 1,2,3-triazole-bound cationic Au(I) catalysts have been synthesized, and their structures have been characterized by X-ray crystallography. Variable-temperature NMR studies revealed dynamic triazole-Au cation coor

Neutral Ti complexes as catalysts for the hydroamination of alkynes and alkenes: Do the labile ligands change the catalytic activity?

A detailed comparison between three four-coordinate Ti complexes featuring the general bidentate ligand [η5-(C5H 4)-SiMe2-NtBu]2- and two ligands X (NMe 2, Me, Cl) as catalyst precursors (I-III) for the intermolecular hydroamination of alkynes and the intramolecular hydroamination of alkenes is presented. The results strongly suggest that the catalytically active species are only identical for reactions performed with the bis(dimethylamido) complex I or the dimethyl complex II. Under the reaction conditions, the labile ligands X are proteolytically removed by the reacting amine to form catalytically active imido or amido complexes, together with dimethylamine or methane. Although both catalyst precursors can be used successfully for many substrate combinations, the preparative and kinetic studies clearly indicate that dimethylamine, which is formed from the bis(dimethylamido) catalyst precursor I and the reacting amine, is able to convert the catalytically active imido or amido complexes back into the catalyst precursor and therefore inhibits the reactions. As a consequence, the bis(dimethylamido) catalyst precursor I shows a poorer catalytic performance than the corresponding dimethyl complex II. Additionally, it is shown that the dichloro complex III is only a suitable catalyst precursor for selected hydroamination reactions. Corresponding reactions that are more difficult to achieve - such as reactions of diarylalkynes or amino alkenes - do not work efficiently with this complex. A possible explanation for this observation is the finding that the dichloro catalyst precursor III is obviously converted into a different catalytically active species. This can happen if the [η5-(C5H4)-SiMe2-NtBu]-ligand system of the catalyst precursor is being destroyed and removed from the Ti center under the reaction conditions. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.

Hydroamination/hydrosilylation sequence catalyzed by titanium complexes

(Chemical Equation Presented) A single precatalyst is used for the sequential combination of the Ti-catalyzed hydroamination of alkynes with the Ti-catalyzed hydrosilylation of imines. In this way alkynes and primary amines are converted efficiently into