121440-87-7Relevant academic research and scientific papers
Palladium-diphosphite catalysts for the asymmetric allylic substitution reactions
Dieguez, Montserrat,Pamies, Oscar,Claver, Carmen
, p. 3363 - 3368 (2005)
(Chemical Equation Presented) We have designed a series of diphosphite ligands to study the effect of the backbone, the size of the chelate ring, and the substituents of the biphenyl moieties and to determine the scope of this type of ligand in the Pd-catalyzed asymmetric substitution reactions of different types of substrates. Good-to-excellent activities and enantioselectivities have been obtained for disubstituted linear substrate 11 (TOF's up to >2000 mol × (mol × h)-1, ee values up to 99%) and cyclic substrate 14 (TOF up to 285 mol × (mol × h) -1, ee values up to 92%). However, these ligands are inadequate for the Pd-catalyzed allylic alkylation of monosubstituted linear substrates because they provide low enantioselectivities.
A remarkable anion effect on the enantioselectivity of the Pd-catalyzed allylic amination using ferrocenyl ligands
Burckhardt, Urs,Baumann, Markus,Togni, Antonio
, p. 155 - 159 (1997)
The effect of several anions on the enantioselectivity of the Pd-catalyzed substitution reaction of 1,3-diphenylprop-2-enylethyl carbonate 1 with benzylamine, utilizing chiral ferrocenyl ligands such as 1-{(R)-1-[(S)-2-(diphenylphosphino)-ferrocenyl]ethyl}- 3-(1-adamantyl)-1H-pyrazole 3a, was investigated. Small hard anions such as F- and BH4-, added in co-catalytic amounts to the catalyst, were found to enhance the ee to >99.5%. On the other hand, non-coordinating anions, e.g. PF6-, had a detrimental effect on the enantioselectivity (10% ee). The beneficial effect of fluoride is discussed in terms of its establishing Curtin-Hammett conditions, by virtue of its coordination to Pd.
Carbamate-based P,O-ligands for asymmetric allylic alkylations
Pálv?lgyi, ádám Márk,Schnürch, Michael,Bica-Schr?der, Katharina
, (2020/05/18)
Herein we report the design and successful catalytic application of modified Trost-ligands in asymmetric allylic alkylation (AAA) reactions. A small set of carbamate-monophosphine P,O-ligands has been prepared in a straightforward two-step synthetic procedure. After optimization of the reaction conditions, high catalytic activities and excellent enantioselectivity up to >99% have been attained.
Optically active 10,10′-spirobi[10H-phenoxasilin]-1,1′-diol: Synthesis, structure, and application of its phosphoramidite derivative to palladium-catalyzed asymmetric allylic amination
Horiuchi, Saki,Kajiyama, Kazumasa,Nishi, Takane,Noda, Seina,Yuge, Hidetaka
supporting information, p. 550 - 552 (2020/07/31)
Optically active (S)-(+)- and (R)-(-)-10,10′-spirobi[10H-phenoxasilin]-1,1′-diols were synthesized by the transesterification of their optically active di-p-toluoyl derivatives resolved by chiral HPLC. The absolute configurations of the optically active s
Catalytic Asymmetric Allylic Amination with Isatins, Sulfonamides, Imides, Amines, and N-Heterocycles
Balaraman, Kaluvu,Lynch, Ciarán C.,Wolf, Christian
supporting information, p. 3180 - 3184 (2020/04/21)
A generally useful palladium-catalyzed method for the asymmetric allylic amination with a large variety of isatins, sulfonamides, imides, amines, and N-heterocycles is introduced. A single protocol with a readily available catalyst accomplishes this reaction at room temperature with high yields and enantioselectivities often exceeding 90%, which is demonstrated with 31 examples.
Design of P-chirogenic aminophosphine-phosphinite ligands at both phosphorus centers: Origin of enantioselectivities in Pd-catalyzed allylic reactions
Jaillet, Antonin,Darcel, Christophe,Bayardon, Jér?me,Schlachter, Adrien,Salomon, Christine,Rousselin, Yoann,Harvey, Pierre,Jugé, Sylvain
, p. 14391 - 14410 (2020/12/29)
We have recently patented an unprecedented stereospecific N → O phosphinyl migration process which transforms P-chirogenic aminophosphines into phosphinites. A fine design of aminophosphine phosphinite ligands (AMPP?) derived from ephedrine and bearing a P-chirogenic center either at the aminophosphine or phosphinite moiety was performed. The synthesis of AMPP? ligands with a P-chirogenic aminophosphine moiety was based on the well-established stereospecific reaction of oxazaphospholidine borane with organolithium reagents, followed by trapping with a chlorophosphine and borane decomplexation. Concurrently, the preparation of AMPP? ligands with a P-chirogenic phosphinite moiety was performed by N → O phosphinyl migration of aminophosphines borane by heating at 50 °C with DABCO and then reaction with chlorophosphines. AMPP? ligands were studied in palladium-catalyzed asymmetric allylic alkylations, leading to enantioselectivities from 91% (R) to 95% ee (S). X-ray crystallographic data for relevant Pd.AMPP? complexes and computer modeling explained the origin of the enantioselectivities based on MO interactions of most stable conformers with nucleophiles.
Towards enantiopure macrocyclic trans-dinucleating hemilabile P-Alkene ligands: Syntheses, structures, and Chiral Pd-Complexes
Frie?, Sibylle,Herrera, Alberto,Linden, Anthony,Heinemann, Frank W.,Dorta, Romano
, (2019/08/13)
Dibenzazepinyl dichlorophosphine 2 reacts with (R,R)-2,3-O-isopropylidene-threitol (3) in Et2O solution to afford gram-quantities of the enantiopure macrocylic phosphoramidite (all-R)-6, which may be seen as a formal dimer of classic phosphoram
Preparation and Application of Amino Phosphine Ligands Bearing Spiro[indane-1,2′-pyrrolidine] Backbone
Feng, Lifei,Jiao, Peng,Li, Hongjie,Li, Shasha,Zhang, Jinxia
, p. 9460 - 9473 (2019/08/26)
P,Nsp3-bidentate chiral ligands bearing spiro[indane-1,2′-pyrrolidine] backbone were prepared in gram scale for the first time. Pd complexes of these air-stable amino phosphine ligands could catalyze asymmetric allylic substitutions of malonate-, alcohol-, and amine-type nucleophiles in up to 97percent ee and 99percent yield. A crystal structure of [Pd(II)(η3-1,3-diphenylallyl)(ligand)]PF6 indicated possible transition states of the catalytic reactions. These ligands are characteristic of a very rigid backbone, which is simple but highly effective. They rival C2-symmetric bisphosphine, P,Nsp2-bidentate, and P,Nsp3-bidentate ligands in tested allylic substitutions. ?
New spiro phosphinooxazolines for palladium-catalyzed asymmetric allylic amination
Gao, Yanfeng,Qiu, Zhongxuan,Sun, Rui,Gao, Nanxing,Cao, Guorui,Teng, Dawei
, p. 3938 - 3941 (2018/10/05)
The new conformational rigid spiro phosphinooxazolines 1 were synthesized from 7-bromo-1-indanone. The asymmetric catalytic potential of them was demonstrated in the asymmetric palladium catalyzed allylic amination. High yields and enantioselectivities were obtained with alkylamines.
Сhiral tricyclic phosphines derived from 1-(+)-neomenthyl-1,2-diphosphole: Synthesis and applications in asymmetric homogeneous catalysis
Zagidullin, Almaz,Miluykov, Vasili,Sinyashin, Oleg,Hey-Hawkins, Evamarie
, (2016/11/11)
A one-step diastereoselective synthesis of bulky P-chiral phosphines with a rigid bicyclic [2.2.1] structure was developed employing a cycloaddition reaction of 3,4,5-triphenyl-1-(+)-neomenthyl-1,2-diphosphole (1) and maleic acid derivatives. The catalyti
