176209-29-3Relevant academic research and scientific papers
Direct Reductive Amination of Carbonyl Compounds with H2 Using Heterogeneous Catalysts in Continuous Flow as an Alternative to N-Alkylation with Alkyl Halides
Laroche, Benjamin,Ishitani, Haruro,Kobayashi, Shū
supporting information, p. 4699 - 4704 (2018/12/04)
A general continuous-flow procedure for direct reductive amination of secondary and primary amines with aromatic and aliphatic aldehydes as well as ketones is reported. The use of hydrogen gas and commercially available Pt/C as a heterogeneous catalyst is a key. In addition to exhibiting an excellent functional group tolerance, this method allows the fast formation of C?N bonds without production of any hazardous chemical waste. Applications to the synthesis of key intermediates toward active pharmaceutical ingredients (Donepezil and Arformoterol/Tamsulosin) are also described. (Figure presented.).
Cyclopropylamines from N,N-dialkylcarboxamides and grignard reagents in the presence of titanium tetraisopropoxide or methyltitanium triisopropoxide
De Meijere, Armin,Chaplinski, Vladimir,Winsel, Harald,Kordes, Markus,Stecker, Bjoern,Gazizova, Vesta,Savchenko, Andrei I.,Boese, Roland,Schill, Farina
supporting information; experimental part, p. 13862 - 13875 (2011/03/18)
Thirty-three different N,N-dialkyl- and N-alkyl-N-phosphorylalkyl- substituted carboxamides 9-17 were treated with unsubstituted as well as with 2-alkyl-, 2,2-dialkyl-, and 3-alkenyl-substituted ethylmagnesium bromides 6 in the presence of stoichiometric amounts of titanium tetraisopropoxide or methyltitanium triisopropoxide to furnish substituted cyclopropylamines 20-25 in 20-98 % yield, depending on the substituents with no (1:1) to excellent (>25:1) diastereoselectivities. Generally higher yields (up to 98 %) of the cyclopropylamines 20-28 without loss of the diastereoselectivity were obtained with methyltitanium triisopropoxide as the titanium mediator. Under these conditions, even dioxolane-protected ketones and halogen-substituted and chiral as well as achiral alkyloxyalkyl-substituted carboxamides could be converted to the correspondingly substituted cyclopropylamines with unsubstituted as well as phenyl- and a variety of alkyl-substituted ethylmagnesium bromides in addition to numerous heteroatom-containing (e.g., halogen-, trityloxy-, tetrahydropyranyloxy-substituted) Grignard reagents (62 examples altogether). The transformation of N,N-diformylalkylamines 54 with ethylmagnesium bromide in the presence of methyltitanium triisopropoxide to N,N-dicyclopropyl-N- alkylamines 55 can be brought about in up to 82 % yield (6 examples). An asymmetric variant of the titanium-mediated cyclopropanation of N,N-dialkylcarboxamides has been developed by applying chiral titanium mediators generated from stoichiometric amounts of titanium tetraisopropoxide and chiral diamino or diol ligands, respectively. The most efficient chiral mediators turned out to be titanium bistaddolates that provided the corresponding cyclopropylamines with enantiomeric excesses (ee) of up to 84 %. Evaluation of several silyl-based additives revealed that the reaction can also efficiently be carried out with substoichiometric amounts (down to 25 Mol %) of the titanium reagent, as long as 2-aryl- or 2-ethenyl-substituted ethylmagnesium halides are used and a concomitant slight decrease in yields is accepted. The newly developed methodology was successfully applied for the preparation of analogues with cyclopropylamine moieties of known drugs and natural products such as the nicotine metabolite (S)-Cotinine as well as the insecticides Dinotefuran and Imidacloprid. Ti is it: Cyclopropylamines have been obtained in low to excellent yield through the reaction of different N,N-dialkyl- and N-alkyl-N- phosphorylalkyl-substituted carboxamides with Grignard reagents in the presence of stoichiometric amounts of titanium tetraisopropoxide or methyltitanium triisopropoxide (see scheme). Copyright
Mechanistic studies of the copper-catalyzed electrophilic amination of diorganozinc reagents and development of a zinc-free protocol
Campbell, Matthew J.,Johnson, Jeffrey S.
, p. 1521 - 1524 (2008/02/02)
Equation Presented An SN2 mechanism for the copper-catalyzed amination of diorganozinc reagents by O-benzoyl-N,N-dialkylhydroxyamines is supported by following stereochemically defined organometallics through the reaction and by employing the endocyclic restriction test. A copper-catalyzed electrophilic amination of organomagnesium compounds is also described in which the use of zinc halides has been eliminated.
Primary 1-Arylcyclopropylamines from aryl cyanides with diethylzinc and titanium alkoxides
Wiedemann, Stefan,Frank, Daniel,Winsel, Harald,De Meijere, Armin
, p. 753 - 755 (2007/10/03)
(Matrix presented) 1-Aryl-substituted primary cyclopropylamines are conveniently prepared from aromatic nitriles and diethylzinc. The yields range from 40 to 56% for donor-substituted (five examples) to 62-82% for non- and acceptor-substituted substrates
Eine nuetzliche Synthese von Cyclopropylaminen aus Carbonsaeuredialkylamiden
Chaplinski, Vladimir,Meijere, Armin de
, p. 491 - 492 (2007/10/03)
Keywords: Amine; Carbonsaeureamide; Cyclopropane; Titanverbindungen
