218937-69-0Relevant articles and documents
Fast continuous alcohol amination employing a hydrogen borrowing protocol
Labes, Ricardo,Mateos, Carlos,Battilocchio, Claudio,Chen, Yiding,Dingwall, Paul,Cumming, Graham R.,Rincón, Juan A.,Nieves-Remacha, Maria José,Ley, Steven V.
supporting information, p. 59 - 63 (2019/01/11)
A continuous flow method for the direct conversion of alcohols to amines via a hydrogen borrowing approach is reported. The method utilises a low loading (0.5%) of a commercial catalyst system ([Ru(p-cymene)Cl2]2 and DPEPhos), reagent grade solvent and is selective for primary alcohols. Successful methylation of amines using methanol and the direct dimethylamination of alcohols using commercial dimethylamine solution are reported. The synthesis of two pharmaceutical agents Piribedil (5) and Buspirone (25) were accomplished in good yields employing these new methods.
Hydroboration Catalyzed by 1,2,4,3-Triazaphospholenes
Tien, Chieh-Hung,Adams, Matt R.,Ferguson, Michael J.,Johnson, Erin R.,Speed, Alexander W. H.
, p. 5565 - 5568 (2017/10/25)
The synthesis and study of the catalytic activity of 1,2,4,3-triazaphospholenes (TAPs) is reported. TAPs represent a more modular scaffold than previously reported diazaphospholenes. TAP halides were shown to catalyze the 1,2 hydroboration of 19 imines, and three α,β unsaturated aldehydes with pinacolborane, including examples that did not undergo hydroboration by previously reported diazaphospholene systems. DFT calculations support a mechanism where a triazaphospholene cation interacts with the substrate, a mechanism distinct from diazaphospholene catalyzed hydroborations.
Asymmetric Imine Hydroboration Catalyzed by Chiral Diazaphospholenes
Adams, Matt R.,Tien, Chieh-Hung,McDonald, Robert,Speed, Alexander W. H.
, p. 16660 - 16663 (2017/12/13)
The first use of diazaphospholenes as chiral catalysts has been demonstrated with enantioselective imine hydroboration. A chiral diazaphospholene prepared in a simple three-step synthesis from commercial materials has been shown to achieve the highest enantioselectivity for the hydroboration of alkyl imines with pinacolborane reported to date. Enantiomer ratios of up to 88:12 were obtained with low (2 mol %) catalyst loadings. Twenty examples of asymmetric reduction employing this main-group catalysis protocol, including the synthesis of the pharmaceuticals ent-rasagiline and fendiline, are shown.
Preparation of N-benzylamines
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, (2008/06/13)
N-Benzylamines are prepared by a process in which (i) in a first step, a benzaldehyde is reacted with a primary amine to give the imine and (ii) in a second step, the imine is hydrogenated with hydrogen in the presence of a catalyst containing one or more metals of groups 8 to 10 of the Periodic Table of the Elements to give the N-benzylamine, wherein the iminization (i) is carried out in a water-miscible solvent and the resulting water of reaction is not removed, and the hydrogenation (ii) is carried out in the imine solution obtained in the iminization (i) and containing water of reaction.
Optically active imidazolidin-2-one derivatives
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, (2008/06/13)
A novel optically active cis-4,5-disubstituted imidazolidin-2-one derivative of the formula: STR1 wherein R1 is a C1 -C4 alkyl group or benzyl and R2 is a chiral aralkyl group optionally having at least one of C1 -C4 alkyl, C1 -C4 alkoxy and hydroxyl groups is produced asymmetrically by the reaction of 1,3-dibenzyl-cis-4,5-dicarboxy-imidazolidin-2-one or its anhydride with an optically active secondary amine of the formula: STR2 wherein R1 and R2 are each as defined above and is transformed into the lactone of 1,3-dibenzyl-cis-4-carboxy-5-hydroxymethyl-imidazolidin-2-one, which is a key intermediate in the synthesis of d-biotin.
