- Straightforward access to cyclic amines by dinitriles reduction
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1,1,3,3-Tetramethyldisiloxane (TMDS) and polymethylhydrosiloxane (PMHS), when associated with titanium(IV) isopropoxide, provide two convenient systems for the reduction of nitriles into the corresponding primary amines. Kinetics of the two systems have been studied by 1H NMR and demonstrated that reduction with PMHS occurs faster than with TMDS. These two titanium-based systems reduce both aromatic and aliphatic nitriles in the presence of Br, CC, NO2, OH, and cyclopropyl-ring. In the case of cyclopropyl-nitriles, the formation of secondary amines, which come from an intermolecular reductive alkylation reaction was observed. This result was exploited for the reduction of dinitriles, which led, in one-step, to azepane, piperidine, pyrrolidine, and azetidine derivatives through an intramolecular reductive alkylation reaction.
- Laval, Stéphane,Dayoub, Wissam,Pehlivan, Leyla,Métay, Estelle,Favre-Reguillon, Alain,Delbrayelle, Dominique,Mignani, Gérard,Lemaire, Marc
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supporting information
p. 975 - 983
(2014/01/23)
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- Asymmetric synthesis of chiral N-sulfinyl 3-alkyl- and 3-arylpiperidines by α-alkylation of N-sulfinyl imidates with 1-chloro-3-iodopropane
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α-Alkylation of N-sulfinyl imidates with 1-chloro-3-iodopropane successfully led to 2-substituted N-tert-butanesulfinyl-5-chloropentanimidates in acceptable diastereomeric ratios (dr 67/33 to 72/28) and good yields (74-86%). Subsequent reduction with NaBH4 led to the corresponding 2-substituted N-tert-butanesulfinyl-5-chloropentylamines, which could be cyclized to a range of new chiral 3-substituted N-tert-butanesulfinylpiperidines using NaH in DMSO. Finally, the N-tert-butanesulfinylpiperidines could be efficiently deprotected to enantiomerically pure 3-alkyl- and 3-arylpiperidine hydrochlorides.
- Colpaert, Filip,Mangelinckx, Sven,De Kimpe, Norbert
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experimental part
p. 234 - 244
(2011/03/19)
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- Ru/C catalyzed cyclization of linear α,ω-diamines to cyclic amines in water
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A facile and convenient way to prepare cyclic amines in water was achieved by the catalyst system composed of Ru/C and Al powder. The α,ω-diaminoalkanes, 1,4-diaminobutane, 1,5-diaminopentane, and 1,6-diamino-heptane were converted to corresponding cyclic amines in good yields. The use of D2O provided a novel route to obtain deuterated cyclic amines in good yields.
- G?dda, Thomas M.,Yu, Xiao-Yan,Miyazawa, Akira
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experimental part
p. 1249 - 1253
(2010/03/30)
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- METHOD FOR SYNTHESISING OPTICALLY ACTIVE PIPERIDINES BY THE HYDROGENATION OF OPTICALLY ACTIVE PYRIDINES
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The invention relates to a method for preparing optically active piperidines by the hydrogenation of pyridines using a suitable catalyst. Said method enables the preparation of a plurality of piperidine derivatives with high optical purity and in high yields.
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Page/Page column 16
(2010/02/12)
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- Synthesis of enantiopure 3-alkyl-perhydroazepines by diastereoselective 7-endo-radical cyclisation on a chiral 1,3-perhydrobenzoxazine derivative
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Competitive alkyl radical 6-exo/7-endo cyclisation on α,β-unsaturated amides derived from chiral perhydrobenzoxazines are controlled by the alkene substitution pattern. Stereocontrol leading to 7-endo regioisomers is considerably higher an allows to prepa
- Andres, Celia,Duque-Soladana, Juan P.,Iglesias, Jesus M.,Pedrosa, Rafael
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p. 2421 - 2424
(2007/10/03)
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