- A Highly Efficient Base-Metal Catalyst: Chemoselective Reduction of Imines to Amines Using An Abnormal-NHC-Fe(0) Complex
-
A base-metal, Fe(0)-catalyzed hydrosilylation of imines to obtain amines is reported here which outperforms its noble-metal congeners with the highest TON of 17000. The catalyst, (aNHC)Fe(CO)4, works under very mild conditions, with extremely low catalyst loading (down to 0.005 mol %), and exhibits excellent chemoselectivity. The facile nature of the imine reduction under mild conditions has been further demonstrated by reducing imines towards expensive commercial amines and biologically important N-alkylated sugars, which are difficult to achieve otherwise. A mechanistic pathway and the source of chemoselectivity for imine hydrosilylation have been proposed on the basis of the well-defined catalyst and isolable intermediates along the catalytic cycle.
- Bhunia, Mrinal,Hota, Pradip Kumar,Vijaykumar, Gonela,Adhikari, Debashis,Mandal, Swadhin K.
-
supporting information
p. 2930 - 2937
(2016/10/06)
-
- Disulfonimide-Catalyzed Asymmetric Reduction of N-Alkyl Imines
-
A chiral disulfonimide (DSI)-catalyzed asymmetric reduction of N-alkyl imines with Hantzsch esters as a hydrogen source in the presence of Boc2O has been developed. The reaction delivers Boc-protected N-alkyl amines with excellent yields and enantioselectivity. The method tolerates a large variety of alkyl amines, thus illustrating potential for a general reductive cross-coupling of ketones with diverse amines, and it was applied in the synthesis of the pharmaceuticals (S)-Rivastigmine, NPS R-568 Hydrochloride, and (R)-Fendiline. A chiral disulfonimide (DSI)-catalyzed asymmetric reduction of N-alkyl imines with Hantzsch esters as a hydrogen source in the presence of Boc2O was developed. The reaction delivers Boc-protected N-alkyl amines with excellent yields and enantioselectivity. The method was successfully applied to the synthesis of the pharmaceuticals (S)-Rivastigmine, NPS R-568 Hydrochloride, and (R)-Fendiline.
- Wakchaure, Vijay N.,Kaib, Philip S. J.,Leutzsch, Markus,List, Benjamin
-
supporting information
p. 11852 - 11856
(2015/10/05)
-
- NHC-carbene cyclopentadienyl iron based catalyst for a general and efficient hydrosilylation of imines
-
A general and efficient hydrosilylation of imines catalysed by a well defined NHC-carbene cyclopentadienyl iron complex has been developed. Both aldimines and ketimines are converted to the corresponding amines under mild conditions, and under visible light activation.
- Castro, Luis C. Misal,Sortais, Jean-Baptiste,Darcel, Christophe
-
supporting information; experimental part
p. 151 - 153
(2012/01/06)
-
- Iridium-catalysed amine alkylation with alcohols in water
-
Amines have been directly alkylated with alcohols using 1 mol% [Cp*IrI2]2 catalyst in water in the absence of base or other additives. The Royal Society of Chemistry 2010.
- Saidi, Ourida,Blacker, A. John,Farah, Mohamed M.,Marsden, Stephen P.,Williams, Jonathan M. J.
-
supporting information; experimental part
p. 1541 - 1543
(2010/06/12)
-
- Borrowing hydrogen in water and ionic liquids: Iridium-catalyzed alkylation of amines with alcohols
-
The use of [Cp*IrI2]2 as an efficient catalyst for the alkylation of amines by alcohols in either water or ionic liquid is described. Primary amines are converted into secondary amines, and secondary amines into tertiary amines in the absence of base, and the chemistry has been applied to the synthesis of the analgesic fentanyl. The conversion of primary amines into N-heterocycles by the reaction with diols is also described, along with the N-alkylation of sulfonamides.
- Saidi, Ourida,Blacker, A. John,Lamb, Gareth W.,Marsden, Stephen P.,Taylor, James E.,Williams, Jonathan M. J.
-
scheme or table
p. 1046 - 1049
(2011/03/20)
-
- A highly enantioselective organocatalytic method for reduction of aromatic N-alkyl ketimines
-
A study has demonstrated the development of a highly enantioselective catalytic method for the reduction of aromatic N-alkyl ketimines by trichlorosilane under mild conditions using the newly designed Lewis base organocatalyst that incorporates C- and S-chirality. The S-chiral sulfinamide group in these catalysts plays a crucial role similar to the carboxamide groups as Lewis base for the activation of HSiCl3, and also serves as a source of chirality that the carboxamide group lacks for the asymmetric induction. The results of the study showed that excellent enantioselectivities of up to 99.6% ee and high yields were obtained for a wide range of substrates. Further works is also in progress to clarify the mechanism of the transformation and explore the full application scope of the present catalyst system.
- Wang, Chao,Wu, Xinjun,Zhou, Li,Sun, Jian
-
supporting information; experimental part
p. 8789 - 8792
(2009/09/25)
-
- Polyoxyalkylene compound and method for making
-
A process for forming a conjugate of a polyoxyalkylene polymer (such as polyethylene glycol) with a compound containing an amine group(s) and/or a sulfide group(s) by reacting the compound with an acrylate terminated polyoxyalkylene (such as polyethylene
- -
-
Page/Page column 7
(2010/02/13)
-
- Hydroamination of carbonyl compounds with oximes
-
N-alkyl(cycloalkyl)benzylamines, p-fluorobenzylamines, (1-phenylethyl) amines, [1-(p-fluorophenyl)ethyl]amines were synthesized by hydroamination of aldehydes and ketones with oximes.
- Tarasevich,Kozlov
-
p. 379 - 383
(2007/10/03)
-
- Reductive amination promoted by tributyltin hydride
-
Reductive amination of carbonyl compounds with primary and secondary ammonium salts was performed by tributyltin hydride in DMF solvent at room temperature. A variety of secondary and tertiary amines including sterically hindered ones could be synthesized in one-pot procedure. No side reaction such as the reduction of starting carbonyl or overalkylation was detected.
- Suwa, Toshihiro,Sugiyama, Erika,Shibata, Ikuya,Baba, Akio
-
p. 556 - 558
(2007/10/03)
-
- Branched alkylamino derivatives of thiazole, processes for preparing them and pharmaceutical compositions containing them
-
The invention relates to the derivatives of formula I: STR1 in which R1 represents a phenyl or naphthyl radical (optionally substituted), R2 represents a hydrogen or halogen atom or an alkyl, hydroxymethyl or formyl radical, R3
- -
-
-
- Tetraalkylammonium Trihydridocyanoborates. Versatile, Selective Reagents for Reductive Aminations in Nonpolar Media
-
Tetrabutylammonium cyanoborohydride or the combination of sodium cyanoborohydride with Aliquat 336 provides useful, convenient reagents for reductive amination of aldehydes and ketones in aprotic or protic media.
- Hutchins, Robert O.,Markowitz, Morris
-
p. 3571 - 3574
(2007/10/02)
-