Various P∗-chiral phosphite-type ligands: their synthesis, stereochemistry and use in Pd-catalysed allylation

Benetsky, Eduard B.; Zheglov, Sergey V.; Grishina, Tatiana B.; Macaev, Fliur; Bet, Liudmila P.; Davankov, V. A.; Gavrilov, K. N.

doi:10.1016/j.tetlet.2007.09.125

Cited by 24 publications

(9 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Zudem diente die Pd-katalysierte allylische Substitution als Testreaktion zur Untersuchung verschiedener einzähniger Phosphorliganden (siehe unten und Liz. [331][332][333][334] [336,337] allerdings konnten keine wesentlichen Verbesserungen der zuvor beschriebenen Methode erreicht werden. Die Pd-katalysierten allylischen Substitutionen von Cyclohexenyl-und Cyclopentenylacetat mit verschiedenen Binaphthyl-und Biphenol-PhosphoramiditLiganden L2 und L16 (siehe Abbildungen 4 und 5) verliefen mit nur schlechten Enantioselektivitäten.…”

Section: Palladiumkatalysierte Allylische Substitutionenunclassified

Phosphoramidite: privilegierte Liganden in der asymmetrischen Katalyse

2010

View full text Add to dashboard Cite

Die asymmetrische Katalyse mit Übergangsmetallkomplexen ist die Grundlage unzähliger stereoselektiver Umwandlungen und hat damit das Bild der modernen Synthesechemie gewandelt. Der Schlüssel zum Erfolg war die Entwicklung chiraler Liganden zur Kontrolle der Regio‐, Diastereo‐ und Enantioselektivität. Dabei haben sich Phosphoramidite als eine äußerst vielseitige und leicht zugängliche Klasse von chiralen Liganden erwiesen. Ihre modulare Struktur ermöglicht die Herstellung von Ligandenbibliotheken und erleichtert die Feinabstimmung für eine bestimmte katalytische Reaktion. Phosphoramidite bewirken oft außerordentlich hohe Stereoselektivitäten, und ihre einzähnige Natur ist in der kombinatorischen Katalyse, die gemischte Liganden verwendet, unverzichtbar. In diesem Aufsatz werden neue Entwicklungen in der asymmetrischen Katalyse mit Phosphoramiditen diskutiert, wobei der Schwerpunkt auf der Bildung von Kohlenstoff‐ Kohlenstoff‐ und Kohlenstoff‐Heteroatom‐Bindungen liegt.

show abstract

Section: Palladiumkatalysierte Allylische Substitutionenunclassified

Phosphoramidite: privilegierte Liganden in der asymmetrischen Katalyse

2010

View full text Add to dashboard Cite

show abstract

“…[9] In particular, phosphoramidites have evolved into a versatile class of ligands since the first reports by Feringa and de Vries [10] showed excellent enantioselectivities in a variety of transition-metal-catalyzed asymmetric processes. [12] The large majority of reported phosphoramidites are composed of a C 2 -symmetric diol backbone (especially BINOL or TADDOL) with a monoamine [13] and, hence, do not feature a P-stereogenic center. [12] The large majority of reported phosphoramidites are composed of a C 2 -symmetric diol backbone (especially BINOL or TADDOL) with a monoamine [13] and, hence, do not feature a P-stereogenic center.…”

Section: Introductionmentioning

confidence: 99%

“…[16] Reetz and Bondarev used (S)-α,α-diphenylprolinol and several alcohols for the synthesis of phosphoramidites of type 6, achivieng up to 95 % ee in the Rh-catalyzed asymmetric hydrogenation. [12] However, previous reports have either not investigated the impact of the Pchirality in catalysis as single diastereomers or diastereomeric mixtures have been employed as ligands for catalysis. [12] However, previous reports have either not investigated the impact of the Pchirality in catalysis as single diastereomers or diastereomeric mixtures have been employed as ligands for catalysis.…”

Section: Introductionmentioning

confidence: 99%

“…[12] However, previous reports have either not investigated the impact of the Pchirality in catalysis as single diastereomers or diastereomeric mixtures have been employed as ligands for catalysis. [12,15,16,17] In a similar strategy, the combination of amino alcohols with monoamines results in phosphorodiamidites (diamidophosphites) containing two P-N and one P-O bond, which consequently possess a stereogenic P-atom. P-Stereogenic phosphoramidites synthesized from amino alcohols containing five-or six-membered 1,3,2-oxaazaphosphacycles.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of P‐Stereogenic Phosphoramidite and Phosphorodiamidite Ligands and Their Application in Asymmetric Catalysis

2015

View full text Add to dashboard Cite

A series of P‐stereogenic monodentate phosphoramidite (PNO2) and phosphorodiamidite (PN2O) ligands based on chiral Betti bases has been prepared by modular synthetic procedures. The chirality at the phosphorus can be controlled to a large extent by the synthetic route, leading to stereoselective access to single P‐epimers. The absolute configuration of the P‐atom was assigned by X‐ray diffraction analysis. The new ligands were evaluated in asymmetric catalysis and the influence of the exocyclic amine or alcohol moiety as well as the interplay between the P‐chirality and the stereocenters in the backbone were investigated. Enantioselectivities of up to 85 and 83 % ee were obtained in the Rh‐catalyzed hydrogenation of dimethyl itaconate and in the Pd‐catalyzed allylic amination of (rac)‐(E)‐1,3‐diphenylallyl acetate with benzylamine, respectively. In the Ni‐catalyzed hydrovinylation of styrene, ee values of up to 68 %, excellent chemoselectivities, and high activities (TOFav up to 3000 h–1) were achieved.

show abstract

“…A new family of readily available modular phosphite, phosphoramidite, and diamidophosphite ligands with P * -stereocenters has been synthesized. Using these novel ligands, high yield was achieved in the Pd-catalyzed asymmetric allylic amination [15].…”

Section: Introductionmentioning

confidence: 99%