24070-12-0Relevant articles and documents
Cesium Hydroxide Promoted Chemoselective N-Alkylation for the Generally Efficient Synthesis of Secondary Amines
Salvatore, Ralph N.,Nagle, Advait S.,Schmidt, Shaun E.,Jung, Kyung Woon
, p. 1893 - 1896 (1999)
(Matrix presented) Selective N-alkylation of primary amines was developed using cesium hydroxide to prepare various secondary amines efficiently. A cesium base not only promoted monoalkylations of primary amines but also suppressed overalkylations. Various amines and alkyl bromides were examined, and the preliminary results demonstrated this methodology was highly chemoselective, favoring mono-N-alkylation over dialkylation. In particular, use of amino acid derivatives afforded the desired secondary amines exclusively.
Microwave-accelerated methodology for the direct reductive amination of aldehydes
Kangasmetsae, Jussi J.,Johnson, Tony
, p. 5653 - 5655 (2007/10/03)
(Chemical Equation Presented) An improved procedure for the direct reductive amination of aldehydes was developed which uses dibutyltin dichloride as catalyst in the presence of phenylsilane as reductant. Rapid reaction is promoted by the use of microwave conditions with anilines, secondary and primary amines being suitable reactants.
Cesium effect: High chemoselectivity in direct N-alkylation of amines
Salvatore, Ralph Nicholas,Nagle, Advait S.,Kyung, Woon Jung
, p. 674 - 683 (2007/10/03)
A novel method for the mono-N-alkylation of primary amines, diamines, and polyamines was developed using cesium bases in order to prepare secondary amines efficiently. A cesium base not only promoted alkylation of primary amines but also suppressed overalkylations of the produced secondary amines. Various amines, alkyl bromides, and alkyl sulfonates were examined, and the results demonstrated this methodology was highly chemoselective to favor mono-N-alkylation over dialkylation. In particular, use of either sterically demanding substrates or amino acid derivatives afforded the secondary amines exclusively, offering wide applications in peptidomimetic syntheses.
Preparation of secondary amines by reductive animation with metallic magnesium
Micovic, Ivan V.,Ivanovic,Roglic, Goran M.,Kiricojevic, Vesna D.,Popovic, Jelena B.
, p. 265 - 269 (2007/10/03)
A novel and efficient method for the preparation of secondary amines by reductive animation of carbonyl compounds with primary amines has been developed. The reduction, effected with metallic magnesium in methanol, utilizing triethylamine-acetic acid as a buffer, gave pure secondary amines, mostly in good yields (65-80%). No formation of tertiary amines or alcohols was observed. Use of ammonium acetate as an amino component gave primary amines in modest yields (ca. 50%), together with variable amounts of secondary amines. Enamines failed to undergo reduction. The method is inexpensive, relatively rapid, operationally simple and suitable for large-scale preparations. In addition, a simple method for separation of primary amines from secondary ones has been developed.
A convergent one-pot synthesis of secondary amines via aza-Wittig reaction
Gajda,Koziara,Osowska-Pacewicka,Zawadzki,Zwierzak
, p. 1929 - 1938 (2007/10/02)
Secondary amines are obtained in moderate-good yields by reduction of crude imines prepared from N-alkyltriethoxyiminophosphoranes and aldehydes via the aza-Wittig reaction. N-Alkyltriethoxyiminophosphoranes are synthesized by one-pot azidation of alkyl bromides followed by Staudinger reaction.
