103808-45-3Relevant academic research and scientific papers
DOTMA-based amides (DOTMAMs) as a platform for the development of PARACEST MRI contrast agents
Suchy,Li,Milne,Bartha,Hudson
, p. 62647 - 62655 (2016)
A synthetic methodology leading to previously unknown DOTMA-based secondary amides (DOTMAMs) has been developed. Alkylation of cyclen with l-lactic acid-derived pseudohalides was used as a key step affording the alkyl- and aryl-decorated DOTMAMs. Amino acid-decorated DOTMAMs were obtained via peptide coupling between DOTMA and protected amino acids. Metallation of the DOTMAMs ligand with Tm3+ gave complexes exhibiting proximal amide proton based paramagnetic CEST effects at -50 ppm relative to water.
Amide bond formation using an air-stable source of AlMe3
Novak, Andrew,Humphreys, Luke D.,Walker, Matthew D.,Woodward, Simon
, p. 5767 - 5769 (2006)
Synthesis of amides from coupling esters with a range of primary amines can be conveniently achieved in moderate to excellent yields (69-99%) using an air-stable adduct of trimethylaluminium (AlMe3)2·DABCO (DABCO is 1,4-diazobicyclo[2.2.2]octane), referred to as DABAL-Me3. Reactions can be run without requiring the exclusion of atmospheric oxygen or the drying of solvents.
Stereoselective Pseudomonas cepacia lipase mediated synthesis of α-hydroxyamides
Adamczyk, Maciej,Grote, Jonathan,Rege, Sushil
, p. 2509 - 2512 (1997)
A new method for the synthesis of α-hydroxyamides via the Pseudomonas cepacia lipase catalyzed amidation of α-hydroxyesters in non-aqueous media is described. Reactivities of α-hydroxy benzyl esters are excellent, resulting in rapid conversions to good yields of α-hydroxyamides, while ethyl and methyl esters react more slowly, and some hindered esters show no reactivity under the conditions studied. Some benzyl esters react stereoselectively, producing excellent yields of asymmetric α-hydroxyamides.
Enzyme-Promoted Asymmetric Tandem Passerini Reaction
??d?o-Dobrowolska, Anna,Koszelewski, Dominik,Paprocki, Daniel,Madej, Arleta,Wilk, Monika,Ostaszewski, Ryszard
, p. 3047 - 3053 (2017/08/14)
A versatile and highly efficient three-step, one-pot, enzyme-promoted Passerini tandem reaction has been developed. The chemoenzymatic sequence involved simultaneous enzyme catalyzed hydrolysis, subsequent Passerini reaction, and enzymatic kinetic resolution of the Passerini product. This methodology combines the diversity delivered by multicomponent reactions with the selectivity of biocatalysts, which results in efficient synthesis of the target compounds with excellent enantiomeric excesses of up to 99 %. With a small set of substrates, a large library of complex molecules was obtained within a short time by using the developed procedure.
Amidation of unactivated ester derivatives mediated by trifluoroethanol
McPherson, Christopher G.,Caldwell, Nicola,Jamieson, Craig,Simpson, Iain,Watson, Allan J. B.
supporting information, p. 3507 - 3518 (2017/04/26)
A catalytic amidation protocol mediated by 2,2,2-trifluoroethanol has been developed, facilitating the condensation of unactivated esters and amines, furnishing both secondary and tertiary amides. The complete scope and limitations of the method are described, along with modified conditions for challenging substrates such as acyclic secondary amines and chiral esters with retention of chiral integrity.
Amides in one pot from Carboxylic Acids and Amines via Sulfinylamides
Bai, Jianfei,Zambron, Bartosz K.,Vogel, Pierre
supporting information, p. 604 - 607 (2014/04/03)
An efficient method has been developed for the direct amidification of carboxylic acids via sulfinylamides preformed in situ by the reaction of pure amines with prop-2- ene-1-sulfinyl chloride. The method can be applied to aliphatic acids, including pivalic acid, aromatic acids, and primary and secondary amines. It is compatible with acids bearing unprotected alcohol, phenol, and ketone moieties and applicable to the synthesis of peptides. It does not induce their a-epimerization.
A [3+3] cyclization strategy for asymmetric synthesis of alkyl substituted piperidine-2-ones using 1,2-cyclic sulfamidates: A formal synthesis of (S)-coniine from l-norvaline
Karanfil, Abdullah,Balta, Berrin,Eskici, Mustafa
, p. 10218 - 10229,12 (2020/09/02)
Regioselective ring-opening reactions of a set of representative 1,2-cyclic sulfamidates with lithium triethylorthopropiolate proceeded efficiently to deliver the corresponding δ-amino-α,β-unsaturated esters after acidic hydrolysis. Hydrogenation of the unsaturated esters and subsequent thermal cyclization afforded the related alkyl substituted piperidine-2-ones. This approach represents a novel [3+3] cyclization strategy for the asymmetric synthesis of alkyl substituted piperidin-2-ones. Efficiency of the cyclization process is illustrated by a formal asymmetric synthesis of (S)-coniine from l-norvaline.
Kinetic resolution of α-bromoamides: Experimental and theoretical investigation of highly enantioselective reactions catalyzed by haloalkane dehalogenases
Westerbeek, Alja,Szymanski, Wiktor,Wijma, Hein J.,Marrink, Siewert J.,Feringa, Ben L.,Janssen, Dick B.
experimental part, p. 931 - 944 (2011/06/19)
Haloalkane dehalogenases from five sources were heterologously expressed in Escherichia coli, isolated, and tested for their ability to achieve kinetic resolution of racemic α-bromoamides, which are important intermediates used in the preparation of bioactive compounds. To explore the substrate scope, fourteen α-bromoamides, with different Cα- and N-substituents, were synthesized. Catalytic activity towards eight substrates was found, and for five of these compounds the conversion proceeded with a high enantioselectivity (E value >200). In all cases, the (R)-α-bromoamide is the preferred substrate. Conversions on a preparative scale with a catalytic amount of enzyme (enzyme:substrate ratio less 1:50 w/w) were all completed within 17-46 h and optically pure α-bromoamides and α-hydroxyamides were isolated with good yields (31-50%). Substrate docking followed by molecular dynamics simulations indicated that the high enantioselectivity results from differences in the percentage of the time in which the substrate enantiomers are bound favourably for catalysis. For the preferred (R)-substrates, the angle between the attacking aspartate oxygen atom of the enzyme, the attacked carbon atom of the substrate, and the displaced halogen atom, is more often in the optimal range (>157°) for reactivity. This can explain the observed enantioselectivity of LinB dehalogenase in a kinetic resolution experiment.
A simple enantioconvergent and chemoenzymatic synthesis of optically active α-substituted amides
Szymanski, Wiktor,Westerbeek, Alja,Janssen, Dick B.,Feringa, Ben L.
supporting information; experimental part, p. 10712 - 10715 (2011/12/05)
Simple and efficient: The combination of an enzymatic, enantioinverting reaction with simple follow-up processes allows the transformation of readily available racemic compounds into versatile chiral α-substituted amides (see picture; Ms=methanesulfonyl).
Catalytic asymmetric transfer hydrogenation of ketones using [Ru(p-cymene)Cl2]2 with chiral amino alcohol ligands
Deshpande, Sudhindra H.,Kelkar, Ashutosh A.,Gonnade, Rajesh G.,Shingote, Savita K.,Chaudhari, Raghunath V.
experimental part, p. 231 - 238 (2011/01/12)
Catalytic asymmetric transfer hydrogenation of aromatic alkyl ketones has been investigated using [Ru(p-cymene)Cl2]2 and new derivatives of β-amino alcohols synthesized from (S)-(-)-lactic acid and mandelic acid as ligands. Chiral secondary alcohols were obtained with good to excellent conversion (60-90%) and moderate to good enantioselectivities (40-86%).
