115859-55-7Relevant articles and documents
Stereoselective synthesis of β-hydroxy-α-amino acids β-substituted with non-aromatic heterocycles
Cremonesi, Giuseppe,Dalla Croce, Piero,Fontana, Francesco,Forni, Alessandra,La Rosa, Concetta
, p. 1667 - 1675 (2007)
We have stereoselectively synthesised β-hydroxy-α-amino acids β-substituted with non-aromatic heterocycles by means of a condensation reaction between enantiomerically pure heterocyclic aldehydes and the (R)-(+)-2,5-dihydro-3,6-dimethoxy-2-isopropylpyrazi
INHIBITORS OF BRUTON'S TYROSINE KINASE AND METHODS OF THEIR USE
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Page/Page column 644, (2017/09/02)
The present disclosure is directed to compounds of formula I and methods of their use and preparation, as well as compositions comprising compounds of formula I.
Highly selective asymmetric Rh-catalyzed hydroformylation of heterocyclic olefins
Chikkali, Samir H.,Bellini, Rosalba,De Bruin, Bas,Van Der Vlugt, Jarl Ivar,Reek, Joost N. H.
experimental part, p. 6607 - 6616 (2012/06/15)
A small family of new chiral hybrid, diphosphorus ligands, consisting of phosphine-phosphoramidites L1 and L2 and phosphine-phosphonites L3a-c, was synthesized for the application in Rh-catalyzed asymmetric hydroformylation of heterocyclic olefins. High-pressure (HP)-NMR and HP-IR spectroscopy under 5-10 bar of syngas has been employed to characterize the corresponding catalyst resting state with each ligand. Indole-based ligands L1 and L2 led to selective ea coordination, while the xanthene derived system L3c gave predominant ee coordination. Application of the small bite-angle ligands L1 and L2 in the highly selective asymmetric hydroformylation (AHF) of the challenging substrate 2,3-dihydrofuran (1) yielded the 2-carbaldehyde (3) as the major regioisomer in up to 68% yield (with ligand L2) along with good ees of up to 62%. This is the first example in which the asymmetric hydroformylation of 1 is both regio- and enantioselective for isomer 3. Interestingly, use of ligand L3c in the same reaction completely changed the regioselectivity to 3-carbaldehyde (4) with a remarkably high enantioselectivity of 91%. Ligand L3c also performs very well in the Rh-catalyzed asymmetric hydroformylation of other heterocyclic olefins. Highly enantioselective conversion of the notoriously difficult substrate 2,5-dihydrofuran (2) is achieved using the same catalyst, with up to 91% ee, concomitant with complete regioselectivity to the 3-carbaldehyde product (4) under mild reaction conditions. Interestingly, the Rh-catalyst derived from L3c is thus able to produce both enantiomers of 3-carbaldehyde 4, simply by changing the substrate from 1 to 2. Furthermore, 85% ee was obtained in the hydroformylation of N-acetyl-3-pyrroline (5) with exceptionally high regioselectivities for 3-carbaldehyde 8Ac (>99%). Similarly, an ee of 86% for derivative 8Boc was accomplished using the same catalyst system in the AHF of N-(tert-butoxycarbonyl)-3-pyrroline (6). These results represent the highest ees reported to date in the AHF of dihydrofurans (1, 2) and 3-pyrrolines (5, 6).
NHC-Catalyzed intramolecular redox amidation for the synthesis of functionalized lactams
Thai, Karen,Wang, Li,Dudding, Travis,Bilodeau, Francois,Gravel, Michel
supporting information; experimental part, p. 5708 - 5711 (2011/03/19)
A very efficient NHC-catalyzed lactamization reaction is reported. For most cases, the ring expansion reaction proceeds to cleanly furnish five- and six-membered N-Ts and N-Bn lactams, without the need for further purification. Evidence is presented suggesting a dual role for the stoichiometric base: (1) deprotonation of the triazolium precatalyst and (2) activation of the nitrogen leaving group through hydrogen bonding.
MELANOCORTIN RECEPTOR AGONISTS
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Page/Page column 47-48, (2010/02/11)
The present invention relates a compound of formula 1, and pharmaceutically acceptable salt, hydrate, solvate, or isomer thereof effective as agonist of melanocortin receptor, and an agonistic composition of melanocortin receptor comprising the same as active ingredient.
Amide-directed hydrocarbonylation of N-alkenylamides and α-alkenyllactams
Ojima, Iwao,Zhang, Zhaoda
, p. 253 - 276 (2007/10/02)
The amide-directed Rh-catalyzed hydroformylation and Pd-catalyzed hydroesterification of N-allylamides give the iso-aldehyde and ester, respectively, with good regioselectivity.The Rh- and Co2Rh2(CO)12-catalyzed reactions of N-methallylamide give an 1-acyl-2-formylpyrrolidine through a novel double carbonylation and an 1-acylpyrrolidine through reductive annulation, respectively, with excellent selectivity.A cyclic hemiamidal, N-benzoyl-2-hydroxy-4-methylpyrrolidine, the key intermediate for the double carbonylation and the reductive annulation, is obtained selectively in a Rh4(CO)12-catalyzed reaction of N-methallylamide.The hydrocarbonylations of this cyclic hemiamidal catalyzed by RhCl(PPh3)3, Co2Rh2(CO)12, and Co2(CO)8 give the corresponding double carbonylation product (2-formylpyrrolidine), reductive annulation product (pyrrolidine), and amidocarbonylation product (proline), respectively, in excellent yield and selectivity.The mechanisms of the novel double carbonylation and the reductive annulation is studied on the basis of deuterium-labeling experiments, and it is found that these reactions proceed via enamide intermediate followed by extremely regioseletive metal hydride addition to the enamide.The Rh-catalyzed hydrocarbonylations of the α-methallyl-γ- and δ-lactams in triethyl orthoformate followed by treatment with TFA give the corresponding 1-azabicycloalkenones via bicyclic hemiamidals through annulation in excellent overall yields.The Co2Rh2(CO)12-catalyzed reactions of these α-methallyl lactams give the corresponding 1-azabicycloalkanones as the sole isolable products in high yields.The RhCl(PPh3)3-catalyzed hydrocarbonylation of 6-allylpiperidin-2-one givesa mixture of 1-azabicyclo and 1-azabicyclo products.However, the addition of phosphines to the Rh catalyst remarkably improves the normal selectivity (n/iso = 9) to give 1-azabicyclodec-2-en-10-one as the predominant product.
Novel Amide-Directed Hydrocarbonylation and Double Carbonylation of N-Allylamides
Ojima, Iwao,Zhang, Zhaoda
, p. 4422 - 4425 (2007/10/02)
The rhodium-catalyzed hydroformylation and palladium-catalyzed hydroesteryfication of N-allylamides give isoaldehyde (1) and isoester (5), respectively, with good regioselectivity through chelation control while the rhodium- and Co2Rh2(CO)12-catalyzed reactions of an N-methallylamide give a novel double carbonylation product (10) and a pyrrolidine (11), respectively, with exellent selectivity.
Synthesis of Analogues of 1,3-Dihydroxyacetone Phosphate and Glyceraldehyde 3-Phosphate for Use in Studies of Fructose-1,6-diphosphate Aldolase
Bischofberger, Norbert,Waldmann, Herbert,Saito, Tohru,Simon, Ethan S.,Lees, Watson,et al.
, p. 3457 - 3465 (2007/10/02)
This paper describes the synthesis of five analogues of dihydroxyacetone phosphate (3-azidohydroxyacetone 1-phosphate (5), 3-(acetylamino)hydroxyacetone 1-phosphate (12), (R)-1,3-dihydroxy-2-butanone 1-phosphate (18), (+/-)-1,3-dihydroxy-2-butanone 3-phosphate (26), and phosphonomethyl glycolate (31)).The syntheses of 18 and 26 are based on a new reaction: that is, the introduction of the phosphate group by the reaction of a diazo ketone with dibenzyl phosphate.These methods provide easy access to a number of compounds that are potential substrates for the synthetically useful enzyme aldolase (fructose-1,6-diphosphate aldolase from rabbit muscle, EC 4.1.2.13, RAMA) and perhaps for other enzymes of glycolysis.This paper also describes syntheses of 14 aldehydes for examination as substrates for aldolase.When the precursor was available, ozonolysis of vinyl groups proved to be the best route to the corresponding aldehydes.
Asymmetric Hydroformylation and Hydrocarboxylation of Enamides. Synthesis of Alanine and Proline
Becker, Y.,Eisenstadt, A.,Stille, J. K.
, p. 2145 - 2151 (2007/10/02)
Carbonyltris(triphenylphosphine)hydridorhodium (1) catalyzed the hydroformylation of N-vinylimides in the presence of optically active 2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)butane (DIOP) or 2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis(5H-dibenzophospholyl)butane (DIPHOL) to afford optically active α-amido aldehydes.Linear disubstituted N-vinylimides or -amides reacted very sluggishly, while the cyclic N-acyl-2-pyrroline (19) was very reactive.In the unsubstituted N-vinylimides moderate (20-40percent ee) asymmetric induction was observed.The optically active α-amido aldehydes were readily converted to the corresponding α-amino acids.Asymmetric hydrocarboxylation of the same substrates in the presence of bis(triphenylphosphine)palladium chloride (2) produced α-amido esters in low optical purity.
