- Conformational Studies by Dynamic NMR. 40. Conformational Atropoisomerism in Highly Hindered Naphthylamines
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N,N-Dialkyl-1-naphthylamines substituted by alkyl groups R (R=Me, Et, i-Pr, t-Bu) in position 2 display anisochronous NMR signals owing to their twisted conformational arrangement.These conformers are enantiomerically related (conformational atropoisomers), and variable temperature NMR measurements allowed the enantiomerization barriers to be determined.The barriers increase with the increasing dimension of the substituents (covering the range 15.7-23.0 kcal mol-1), and the observed trend was reproduced by Molecular Mechanics calculations.The calculations also gaveindications upon the structure of the conformers that correspond to energy minima.The final choice among the possible conformations could be achieved by comparing the computed interprotonic distances with the results of NOE experiments.
- Davalli, S.,Lunazzi, L.,Macciantelli, D.
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Read Online
- Efficient hydrogenation catalyst designing via preferential adsorption sites construction towards active copper
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Based on the experimental and DFT calculation results, here for the first time we built preferential adsorption sites for nitroarenes by modification of the supported Cu catalysts surface with 1,10-phenathroline (1,10-phen), by which the yield of aniline via reduction of nitroarene is enhanced three times. Moreover, a macromolecular layer was in-situ generated on supported Cu catalysts to form a stable macromolecule modified supported Cu catalyst, i.e., CuAlOx-M. By applying the CuAlOx-M, a wide variety of nitroarene substrates react smoothly to afford the desired products in up to > 99% yield with > 99% selectivity. The method tolerates a variety of functional groups, including halides, ketone, amide, and C = C bond moieties. The excellent catalytic performance of the CuAlOx-M can be attributed to that the 1,10-phen modification benefits the preferential adsorption of nitrobenzene and slightly weakens adsorption of aniline on the supported nano-Cu surface.
- Dai, Xingchao,He, Dongcheng,Li, Teng,Shi, Feng,Wang, Hongli,Wang, Tao,Wang, Xinzhi
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p. 397 - 406
(2021/07/21)
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- Synthesis of sterically congested 1,5-disubstituted-1,2,3-Triazoles using chloromagnesium acetylides and hindered 1-naphthyl azides
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Sterically congested 1-(2-methoxy-1-naphthyl)-5-substituted-1,2,3-triazoles can be prepared from sterically hindered 2-methoxy-1-azidonaphthalene and chloromagnesium acetylides, including 2-substituted phenylacetylides. Catalytic methods using Cp?RuCl(PPh
- Mahadari, Muni Kumar,Tague, Andrew J.,Keller, Paul A.,Pyne, Stephen G.
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- Cobalt-Catalyzed Direct Carbonylative Synthesis of Free (NH)-Benzo[ cd]indol-2(1 H)-ones from Naphthylamides
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A cobalt-catalyzed C-H carbonylation of naphthylamides for the synthesis of benzo[cd]indol-2(1H)-one scaffolds has been developed. The reaction employs a traceless directing group and uses benzene-1,3,5-triyl triormate as the CO source, affording various free (NH)-benzo[cd]indol-2(1H)-ones in moderate to high yields (up to 88%). Using this protocol, the total synthesis of BET bromodomain inhibitors A and B was accomplished as well.
- Ying, Jun,Fu, Lu-Yang,Zhong, Guoqiang,Wu, Xiao-Feng
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supporting information
p. 5694 - 5698
(2019/07/08)
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- Exploring the Catalytic Reactivity of Nickel Phosphine-Phosphite Complexes
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In this study, we present an investigation into various nickel phosphite and phosphite-phosphine complexes for use in the Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions and the ammonia arylation reaction. In these coupling reactions, it was discovered that the Ni[P(OEt)3]4, (dppf)Ni[P(OPh)3]2, and (binap)Ni[P(OPh)3]2 catalysts were the most effective. In addition, an optimisation process for these catalytic systems as well as functional group compatibility are discussed.
- Kampmann, Sven S.,Man, Nikki Y. T.,McKinley, Allan J.,Koutsantonis, George A.,Stewart, Scott G.
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p. 1842 - 1853
(2015/12/26)
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- Methylterrylene isomers
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2-Methyl and 3-methylterrylenes have been obtained by Suzuki coupling of 3-bromoperylene and corresponding methylnaphthylboronic acids or esters, giving methylnaphthylperylene isomers, followed by Scholl cyclodehydrogenation; the latter reaction gave also the other cyclodehydrogenation isomers 10- (respectively, 9-) methylbenzo[4,5]indeno[1,2,3-cd]perylene.
- Nagarajan, Samuthira,Barthes, Cecile,Girdhar, Navdeep K.,Dang, Tung T.,Gourdon, Andre
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p. 9371 - 9375,5
(2012/12/12)
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- Synthesis of primary aryl amines through a copper-assisted aromatic substitution reaction with sodium azide
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(Figure Presented) A method is presented by which aryl halides and azides are converted to the corresponding primary aryl amines with copper(I) and sodium azide.
- Markiewicz, John T.,Wiest, Olaf,Helquist, Paul
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supporting information; experimental part
p. 4887 - 4890
(2010/10/19)
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- Catalytic complexes and their use for polymerizing alpha-olefins
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A complex of a transition metal complying with the general formula (I) in which M is a transition metal of groups 6 to 12, T is the oxidation state of M, each A, which may be identical with or differ from each other, is an atom or an atomic grouping bonded covalently or ionically to the transition metal M, b is the valency of A, each R1, R2, R3, R4 and R5 is independently a hydrogen atom, an unsubstituted or substituted hydrocarbon group, an unsubstituted or substituted heterohydrocarbon group, or an inert functional group, R6 and R7 are, independently of one another, a polynuclear aromatic hydrocarbon group containing at least two condensed benzene nuclei, substituted with at least one hydrocarbon group.
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- First use of axially chiral thioamides for the stereocontrol of C-C bond formation
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Several N-aryl-substituted thioamides with an axis of chirality along the N-C(aryl) bond were prepared in good to excellent yields. NMR spectra revealed preferences for the E rotamer (along the N-C(=S) bond). X-ray crystallographic analysis showed that the planes of the aryl and thioamide groups were almost perpendicular (79°). For the first time, these atropisomeric thioamides were used for an asymmetric Claisen rearrangement. LDA deprotonation led selectively to the enethiolates of Z stereochemistry, and subsequent reaction with a variety of allyl halides furnished S-allyl keteneaminothioacetals. These intermediates were not detected as they rearranged readily to γ-unsaturated thioamides in good to high yields and diastereoselectivities up to 88:12. Chemical correlation allowed the assignment of the (aR*,2R*) configuration to the major diastereoisomer. A model was proposed to explain the stereochemical course of the thio-Claisen rearrangement.
- Dantale, Shubhada,Reboul, Vincent,Metzner, Patrick,Philouze, Christian
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p. 632 - 640
(2007/10/03)
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- Catalytic complexes and their use for polymerizing alpha-olefins
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A complex of a transition metal complying with the general formula (I) in whichM is a transition metal of groups 6 to 12,T is the oxidation state of M,each A, which may be identical with or differ from each other, is an atom or an atomic grouping bonded covalently or ionically to the transition metal M,b is the valency of A,each R1, R2, R3, R4 and R5 is independently a hydrogen atom, an unsubstituted or substituted hydrocarbon group, an unsubstituted or substituted heterohydrocarbon group, or an inert functional group,R6 and R7 are, independently of one another, a polynuclear aromatic hydrocarbon group containing at least two condensed benzene nuclei, substituted with at least one hydrocarbon group.
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- Direct Photoamination of Arenes with Ammonia and Primary Amines in the Presence of Electron Acceptors
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Direct photoamination of phenanthrene, 9-methoxyphenanthrene, anthracene, naphthalene, and several substituted naphthalenes with ammonia or primary amines in the presence of m-dicyanobenzene occurs to give aminated dihydroarenes in fairly good yields. m-Dimethoxybenzene and biphenyl are photoaminated in lower yields.A suggested mechanism for the photoamination involves the nucleophilic attack of ammonia and amines on aromatic cation radicals generated by photochemical electron transfer to m-dicyanobenzene.The present photoamination is applied to direct introduction of various functionalized primary amines containing the vinyl, cyano, hydroxy, acetylamino, and ethoxycarbonyl groups.
- Yasuda, Masahide,Yamashita, Toshiaki,Shima, Kensuke,Pac, Chyongjin
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p. 753 - 759
(2007/10/02)
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- Methylterrylene isomers
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2-Methyl and 3-methylterrylenes have been obtained by Suzuki coupling of 3-bromoperylene and corresponding methylnaphthylboronic acids or esters, giving methylnaphthylperylene isomers, followed by Scholl cyclodehydrogenation; the latter reaction gave also the other cyclodehydrogenation isomers 10- (respectively, 9-) methylbenzo[4,5]indeno[1,2,3-cd]perylene.
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