- Titanium-Catalyzed Hydroaminoalkylation of Ethylene
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The first examples of titanium-catalyzed hydroaminoalkylation reactions of ethylene with secondary amines are presented. The reactions can be achieved with various titanium catalysts and they do not require the use of high pressure equipment. In addition, the first solid-state structure of a titanapyrrolidine that is formed by insertion of an alkene into the Ti?C bond of a titanaaziridine is reported.
- Rosien, Michael,T?ben, Iris,Schmidtmann, Marc,Beckhaus, Rüdiger,Doye, Sven
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supporting information
p. 2138 - 2142
(2020/02/05)
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- Catalytic hydrogenation of amides to amines under mild conditions
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Under (not so much) pressure: A general method for the hydrogenation of tertiary and secondary amides to amines with excellent selectivity using a bimetallic Pd-Re catalyst has been developed. The reaction proceeds under low pressure and comparatively low temperature. This method provides organic chemists with a simple and reliable tool for the synthesis of amines. Copyright
- Stein, Mario,Breit, Bernhard
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supporting information
p. 2231 - 2234
(2013/03/28)
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- Regioselective synthesis of heterocycles containing nitrogen neighboring an aromatic ring by reductive ring expansion using diisobutylaluminum hydride and studies on the reaction mechanism
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(Chemical Equation Presented) A systematic investigation of the reductive ring-expansion reaction of cyclic ketoximes fused to aromatic ringswith diisobutylaluminum hydride (DIBALH) is described. This reaction regioselectively afforded a variety of five- to eight-membered bicyclic heterocycles or tricyclic heterocycles containing nitrogen neighboring an aromatic ring, including indoline, 1,2,3,4,5,6-hexahydrobenz[b]azocine, 3,4-dihydro-2H-benzo[b] [1,4]oxazine, 2,3,4,5-tetrahydrobenzo[b][1,4]thiazepine, 1,2,3,4,5,6- hexahydroazepino[3,2-b]-indole, 2,3,4,5-tetrahydro-1H-benzothieno[2,3-b]azepine, 2,3,4,5-tetrahydro-1H-benzothieno[3,2-b]-azepine, 5,6-dihydrophenanthridine, and 5,6,11,12-tetrahydrodibenz[b, f]azocine. The reaction mechanism leading to the rearrangement was investigated on the basis of the restricted Becke three-parameter plus Lee-Yang-Parr (B3LYP) density functional theory (DFT) with the 6-31G (d) basis set. It was found that the reaction proceeds through a three-centered transition state via a stepwise mechanism because the potential energy curve along the intrinsic reaction coordinate (IRC) had twomaxima (saddle points; TS1 and TS2) and the partial phenonium cation intermediate C. In addition to cyclic ketoximes fused to aromatic rings, the reactions of various cyclic and acyclic ketoximeswere examined to investigate preference of migrating group. It was found that themore electron-rich group migrated preferentially to give the corresponding secondary amines.
- Cho, Hidetsura,Iwama, Yusuke,Sugimoto, Kenji,Mori, Seiji,Tokuyama, Hidetoshi
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experimental part
p. 627 - 636
(2010/04/29)
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- Carbon versus phosphorus site selectivity in the gas-phase anion-molecule reactions of dimethyl methylphosphonate
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The reactions of dimethyl methylphosphonate and its conjugate base with a variety of anions and neutral substrates, respectively, have been examined with use of the thermally equilibrated conditions (298 K) of the flowing afterglow. The conjugate base of dimethyl methylphosphonate reacts readily with alcohols and carbonyl compounds; its reaction with alcohols yields products from proton transfer, proton transfer followed by substitution at carbon, and proton transfer followed by substitution at phosphorus, while its reaction with carbonyl compounds generates products from proton transfer, Horner-Emmons-Wadsworth reaction, addition/elimination, and adduct formation. Dimethyl methylphosphonate undergoes facile reaction with a diverse set of anions ranging in base strength from amide to hydrogen sulfide and in structure from localized heteroatomic bases and localized carbon bases to delocalized carbanions. Four reaction pathways account for the interaction of anions with dimethyl methylphosphonate: proton transfer, nucleophilic substitution at carbon, reductive elimination, and nucleophilic substitution at phosphorus. Proton transfer and nucleophilic substitution at carbon dominate all reactions, while reductive elimination is observed only for the strongest base examined, amide. Methoxide and fluoride are the only anions that react at phosphorus. A reaction coordinate diagram is used to interpret the reactions of dimethyl methylphosphonate and its conjugate base. The acidity of dimethyl methylphosphonate was bracketed to be ΔHoacid[(CH3O)2(CH 3)PO] = 373 ± 3 kcal mol-1.
- Lum, Rachel C.,Grabowski, Joseph J.
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p. 7823 - 7832
(2007/10/02)
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- ELECTROCHEMICAL REDUCTIVE AMINATION. II. AMINATION OF ALIPHATIC ALDEHYDES WITH PRIMARY AMINES
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The formation of a secondary amine by the electrolysis of an aqueous solution containing an aldehyde and a primary amine was studied.The formation of the secondary amines passes through the intermediate stage of an aldimine.The highest yield of secondary amine is attained at a molar ratio of primary amine to aldehyde of 1.2:1.As electrode material lead, cadmium, zinc, and copper may be used.As supporting electrolyte a phosphate buffer with a pH close to the pKa of the primary amine is recommended.By the method developed 32 amines with various structures were synthesized.
- Smirnov, Yu. D.,Pavlichenko, V. F.,Tomilov, A. P.
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p. 374 - 380
(2007/10/02)
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- Substituted benzofurans and benzothiophenes
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The compounds are benzoyl benzofurans and benzothiophenes having pharmacological activity, in particular, coronary vasodilator activity useful for the treatment of angina pectoris and intermediates for the preparation thereof.
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