222415-35-2Relevant articles and documents
Iridium-Catalyzed α-Selective Arylation of Styrenes by Dual C?H Functionalization
Cooper, Phillippa,Crisenza, Giacomo E. M.,Feron, Lyman J.,Bower, John F.
supporting information, p. 14198 - 14202 (2018/10/02)
An IrI-system modified with a ferrocene derived bisphosphine ligand promotes α-selective arylation of styrenes by dual C?H functionalization. These studies offer a regioisomeric alternative to the Pd-catalyzed Fujiwara–Moritani reaction.
Highly Enantioselective Iridium-Catalyzed Hydrogenation of Cyclic Enamides
Salomó, Ernest,Orgué, Sílvia,Riera, Antoni,Verdaguer, Xavier
supporting information, p. 7988 - 7992 (2016/09/13)
The MaxPHOX–Ir catalyst system provided the highest selectivity ever reported for the reduction of cyclic enamides derived from α- and β-tetralones. This result indicates that iridium catalysts are also proficient in reducing alkenes bearing metal-coordinating groups. In the present system, selectivity was pressure-dependent: In most cases, a decrease in the H2pressure to 3 bar resulted in an increase in enantioselectivity. Moreover, the process can be carried out in environmentally friendly solvents, such as methanol and ethyl acetate, with no loss of selectivity.
Directing group assisted nucleophilic substitution of propargylic alcohols via o -quinone methide intermediates: Br??nsted acid catalyzed, highly enantio- and diastereoselective synthesis of 7-alkynyl-12a-acetamido-substituted benzoxanthenes
Saha, Satyajit,Schneider, Christoph
supporting information, p. 648 - 651 (2015/03/05)
BINOL-based, chiral phosphoric acids catalyze the substitution of 1-(o-hydroxyphenyl)propargylic alcohols with enamides to furnish 7-alkynyl-12a-acetamido-substituted benzo[c]xanthenes and related heterocycles in a one-pot operation with excellent diastereo- and enantioselectivity. Ambient reaction temperature, operationally simple reaction conditions, low catalyst loading, high yields, and excellent stereocontrol are attractive features of this process and make it a highly practical and versatile transformation.
Asymmetric hydrogenation using rhodium complexes generated from mixtures of monodentate neutral and anionic phosphorus ligands
Frank, Dominik J.,Franzke, Axel,Pfaltz, Andreas
supporting information, p. 2405 - 2415 (2013/03/28)
A series of monodentate neutral and anionic phosphorus ligands was synthesized and evaluated in the asymmetric rhodium-catalyzed hydrogenation of functionalized olefins by using either catalysts containing identical ligands or catalysts generated from mixtures of two different ligands. We expected that the combination of an anionic ligand with a neutral ligand would favor the formation of hetero over homo bis-ligand complexes due to charge repulsion. NMR spectroscopic studies confirmed that charge effects can indeed shift the equilibrium toward the hetero bis-ligand complexes. In several cases, the combination of a neutral phosphane with an anionic phosphane, one chiral and the other achiral, furnished significantly higher enantioselectivities than analogous mixtures of two neutral ligands. The best results were obtained with a mixture of an anionic phosphoramidite and a neutral phosphoric acid diester. It is supposed that in this case a hydrogen bond between the two ligands additionally stabilizes the hetero ligand combination. Charge effects and hydrogen bonding favor the formation of rhodium hetero bis-ligand complexes from mixtures of neutral and anionic monodentate phosphorus ligands. The combination of a neutral phosphoric acid diester as a hydrogen donor and an anionic phosphoramidite as a hydrogen acceptor gives very high enantioselectivities in Rh-catalyzed hydrogenation reactions, thus exceeding the ee values of the corresponding homo bis-ligand complexes (see scheme). Copyright
Design of phosphorus ligands with deep chiral pockets: Practical Synthesis of chiral β-arylamines by asymmetric hydrogenation
Liu, Guodu,Liu, Xiangqian,Cai, Zhihua,Jiao, Guangjun,Xu, Guangqing,Tang, Wenjun
supporting information, p. 4235 - 4238 (2013/05/08)
WingPhos, a C2-symmetric bisphosphorus ligand with a deep and well-defined chiral pocket was developed. It has shown high efficiency in the rhodium-catalyzed asymmetric hydrogenation of (E)-β-aryl-N-acetyl enamides, cyclic β-aryl enamides, and heterocyclic β-aryl enamides. A series of chiral β-arylisopropylamines, 2-aminotetralines, and 3-aminochromans can be synthesized with excellent ee values (nbd=3,5-norbornadiene; TON=turnover number). Copyright
Rhodium phosphine-phosphite catalysts in the hydrogenation of challenging N-(3,4-dihydronaphthalen-2-yl) amide derivatives
Arribas, Inmaculada,Rubio, Miguel,Kleman, Patryk,Pizzano, Antonio
, p. 3997 - 4005 (2013/06/26)
The enantioselective catalytic hydrogenation of N-(3,4-dihydronaphthalen-2- yl) amides (1) with rhodium catalysts bearing phosphine-phosphite ligands 4 has been studied. A wide catalyst screening, facilitated by the modular structure of 4, has found a hig
Enantiomerically Enriched Aminodiphosphines as Ligands for the Preparation of Catalysts for Asymmetric Synthesis
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Page/Page column 14, (2012/12/14)
The present invention relates to enantiomerically enriched aminodiphosphine ligands where the chirality is located in the phosphorus atom and their preparation process, to catalysts containing them and their preparation process, as well as their use in as
Asymmetric hydrogenation of trisubstituted N-acetyl enamides derived from 2-tetralones using ruthenium-SYNPHOS catalysts: A practical synthetic approach to the preparation of β3-adrenergic agonist SR58611A
Pautigny, Cyrielle,Debouit, Charlotte,Vayron, Philippe,Ayad, Tahar,Ratovelomanana-Vidal, Virgine
experimental part, p. 1382 - 1388 (2010/10/21)
The asymmetric hydrogenation of various trisubstituted enamides derived from 2-tetralones under mild reaction conditions using Ru-SYNPHOS catalysts is reported. This practical and clean method gives access to several chiral 2-aminotetralins derivatives in high isolated yields and enantiomeric excesses up to 95% depending on the substitution pattern of the aromatic ring and the nature of the amide moiety. In addition, the usefulness of the current method is demonstrated via a practical synthetic approach to the enantiomerically pure SR58611A compound, a potent and selective β3-adrenergic receptor agonist.
New process for the synthesis of enamide derivatives
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Page/Page column 6, (2008/06/13)
A process for the production of ene-amide derivatives represented by the formula (I) wherein R1 and R2 and R3 are independently a hydrogen atom, an alkyl, a cycloalkyl, a cycloalkylalkyl, an alkylaryl, an aryl, a heterocycle, a cyano, an acyl, an alkoxy, an aryloxy, a carboxyl, a carbamoyl, -CONR5R6 (in which R5 and R6 are independently an alkyl, arylalkyl or aryl group) or -COOR5 group (in which R5 is an alkyl, alkylaryl or aryl group), said alkyl, cycloalkyl, cycloalkylalkyl, alkylaryl and aryl groups being substituted or not with a functional group or with R5; or R1 and R2 taken together, may form a ring (which terms includes mono-, di- and higher polycyclic ring systems); R3 has the same meanings as R1 or R3 is a hydroxyl, imidazolyl, N-acylimidazolyl, indolyl, N-acylindolyl group or one of the groups, - COR5, -OR5, -OCOR5, -NR5R6, -NHCOR5, -N(COR5)2, wherein R5 and R6 are independently an alkyl, alkylaryl or aryl group; R4 is a hydrogen atom, an alkyl, an aryl, an alkylaryl, said groups are substituted or not with a halogen atom as Cl, Br, or F; Y is a hydrogen atom or R4CO group; X is an oxygen atom or a leaving group and m is an integer 1 or 2; when m is 1 then X is a leaving group; when m is 2 then X is a oxygen atom, which comprise : a hydrogenation/isomerization reaction in presence of a heterogeneous catalyst, of an oxime derivatives of formula (II) wherein R1, R2 and R3 are as defined above with an acyl derivative of formula (III) (R4CO)mX wherein R4, m and X are as defined above.
Ruthenium-Catalysed Enantioselective Hydrogenation of Trisubstituted Enamides Derived from 2-Tetralone and 3-Chromanone: Influence of Substitution on the Amide Arm and the Aromatic Ring
Renaud,Dupau,Hay,Guingouain,Dixneuf,Bruneau
, p. 230 - 238 (2007/10/03)
Cyclic enamides were prepared in one step from tetralone and chromanone derivatives and primary amides under acidic conditions. The enantio-selective hydrogenation of these enamides bearing an endocyclic trisubstituted carbon-carbon double bond was perfor