153233-81-9Relevant articles and documents
Copper(I) Phosphinooxazoline Complexes: Impact of the Ligand Substitution and Steric Demand on the Electrochemical and Photophysical Properties
Frey, Wolfgang,Giereth, Robin,Karnahl, Michael,Klo?, Marvin,Mengele, Alexander K.,Steffen, Andreas,Tschierlei, Stefanie
, p. 2675 - 2684 (2020/03/04)
A series of seven homoleptic CuI complexes based on hetero-bidentate P^N ligands was synthesized and comprehensively characterized. In order to study structure–property relationships, the type, size, number and configuration of substituents at the phosphinooxazoline (phox) ligands were systematically varied. To this end, a combination of X-ray diffraction, NMR spectroscopy, steady-state absorption and emission spectroscopy, time-resolved emission spectroscopy, quenching experiments and cyclic voltammetry was used to assess the photophysical and electrochemical properties. Furthermore, time-dependent density functional theory calculations were applied to also analyze the excited state structures and characteristics. Surprisingly, a strong dependency on the chirality of the respective P^N ligand was found, whereas the specific kind and size of the different substituents has only a minor impact on the properties in solution. Most importantly, all complexes except C3 are photostable in solution and show fully reversible redox processes. Sacrificial reductants were applied to demonstrate a successful electron transfer upon light irradiation. These properties render this class of photosensitizers as potential candidates for solar energy conversion issues.
Sulfoxide ligand metal catalyzed oxidation of olefins
-
, (2019/05/09)
The enantioselective synthesis of isochroman motifs has been accomplished via Pd(II)-catalyzed allylic C—H oxidation from terminal olefin precursors. Critical to the success of this goal was the development and utilization of a novel chiral aryl sulfoxide-oxazoline (ArSOX) ligand. The allylic C—H oxidation reaction proceeds with the broadest scope and highest levels asymmetric induction reported to date (avg. 92% ee, 13 examples ≥90% ee). Additionally, C(sp3)-N fragment coupling reaction between abundant terminal olefins and N-triflyl protected aliphatic and aromatic amines via Pd(II)/sulfoxide (SOX) catalyzed intermolecular allylic C—H amination is disclosed. A range of 52 allylic amines are furnished in good yields (avg. 76%) and excellent regio- and stereoselectivity (avg. >20:1 linear:branched, >20:1 E:Z). For the first time, a variety of singly activated aromatic and aliphatic nitrogen nucleophiles, including ones with stereochemical elements, can be used in fragment coupling stiochiometries for intermolecular C—H amination reactions.
Synthesis of multisubstituted pyrroles by nickel-catalyzed arylative cyclizations of: N -tosyl alkynamides
Gillbard, Simone M.,Chung, Chieh-Hsu,Karad, Somnath Narayan,Panchal, Heena,Lewis, William,Lam, Hon Wai
supporting information, p. 11769 - 11772 (2018/11/10)
The synthesis of multisubstituted pyrroles by the nickel-catalyzed reaction of N-tosyl alkynamides with arylboronic acids is reported. These reactions are triggered by alkyne arylnickelation, followed by cyclization of the resulting alkenylnickel species
Asymmetric Allylic C-H Alkylation via Palladium(II)/ cis-ArSOX Catalysis
Liu, Wei,Ali, Siraj Z.,Ammann, Stephen E.,White, M. Christina
, p. 10658 - 10662 (2018/09/06)
We report the development of Pd(II)/cis-aryl sulfoxide-oxazoline (cis-ArSOX) catalysts for asymmetric C-H alkylation of terminal olefins with a variety of synthetically versatile nucleophiles. The modular, tunable, and oxidatively stable ArSOX scaffold is key to the unprecedented broad scope and high enantioselectivity (37 examples, avg. > 90% ee). Pd(II)/cis-ArSOX is unique in its ability to effect high reactivity and catalyst-controlled diastereoselectivity on the alkylation of aliphatic olefins. We anticipate that this new chiral ligand class will find use in other transition metal catalyzed processes that operate under oxidative conditions.
Enantioselective Allylic C?H Oxidation of Terminal Olefins to Isochromans by Palladium(II)/Chiral Sulfoxide Catalysis
Ammann, Stephen E.,Liu, Wei,White, M. Christina
, p. 9571 - 9575 (2016/08/10)
The enantioselective synthesis of isochroman motifs has been accomplished by palladium(II)-catalyzed allylic C?H oxidation from terminal olefin precursors. Critical to the success of this goal was the development and utilization of a novel chiral aryl sul
Ring-opening polymerization of rac-lactide with aluminum chiral anilido-oxazolinate complexes
Bian, Shi,Abbina, Srinivas,Lu, Zhengliang,Kolodka, Edward,Du, Guodong
, p. 2489 - 2495 (2014/06/10)
A series of dimethylaluminum complexes (L1a-i)AlMe2 (2a-i, where HL1a-i = 2-(2′-ArNH)phenyl-4-R1- oxazoline) bearing chiral, bidentate anilido-oxazolinate ligands have been prepared and characterized. Six of the
Bis(perfluoroalkyl) phosphino-oxazoline: A modular, stable, strongly π-accepting ligand for asymmetric catalysis
Hu, Zongjian,Li, Yuguang,Liu, Kai,Shen, Qilong
, p. 7957 - 7967 (2013/01/15)
A new class of stable, strongly π-accepting and modular bis-(perfluoroalkyl)-phosphine-oxazoline ligands (FOX) as CO mimics was prepared. It was demonstrated that these ligands, when coordinated to palladium catalysts, promote the asymmetric alkylation of monosubstituted allyl substrates with excellent regio- and enantioselectivity. Solid and solution structure analysis of the FOX-ligated Pd-allyl intermediate reveals that the combination of relative steric and strong trans influences presented by the P(CF 3)2 moiety gave rise to the excellent selectivity.
Modular synthesis of chiral β-diketiminato-type ligands containing 2-oxazoline moiety via palladium-catalyzed amination
Binda, Pascal I.,Abbina, Srinivas,Du, Guodong
supporting information; experimental part, p. 2609 - 2618 (2011/10/04)
A family of new chiral β-diketiminato-type ligands containing oxazoline moiety has been synthesized in moderate to high yields (typically 30-95%) via a Pd-catalyzed amination reaction of chiral oxazolines with primary amines and amides. Notably, (S)-tert-
C1-symmetric oxazolinyl sulfoximines as ligands in copper-catalyzed asymmetric mukaiyama aldol reactions
Sedelmeier, Joerg,Hammerer, Tim,Bolm, Carsten
supporting information; experimental part, p. 917 - 920 (2009/04/07)
Aryl-bridged C1-symmetric oxazolinyl sulfoximines are applicable in copper-catalyzed asymmetric Mukaiyama aldol reactions with methyl pyruvate. The resulting a-hydroxy esters have been obtained with up to 94% ee in good yields. They contain a quaternary stereogenic center and represent valuable precursors for biologically active molecules.
