154701-60-7Relevant articles and documents
Sulfoxide ligand metal catalyzed oxidation of olefins
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Page/Page column 55, (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.
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
The synthesis of phosphine oxide-linked bis(oxazoline) ligands and their application in asymmetric allylic alkylation
Jin, Yu,Du, Da-Ming
, p. 3633 - 3640 (2012/06/18)
The phosphine oxide-linked bis(oxazoline) ligands were designed and synthesized in two ways. One is the coupling of Grignard reagent derived from 2-(2-bromophenyl)oxazoline with phenylphosphonic dichloride, another route is the condensation of bis(2-formylphenyl)(phenyl)phosphine oxide with chiral amino alcohols followed by NBS oxidation. These new bis(oxazoline) ligands were applied in Pd-catalyzed asymmetric allylic alkylation reactions and good yields and enantioselectivities were obtained with diphenyl substituted ligand (up to 95% ee).
A general, asymmetric, and noniterative synthesis of trideoxypropionates. Straightforward syntheses of the pheromones (+)-vittatalactone and (+)-norvittatalactone
Weise, Christian F.,Pischl, Matthias C.,Pfaltz, Andreas,Schneider, Christoph
, p. 1477 - 1488 (2012/04/04)
A novel, highly stereocontrolled, and very flexible synthetic access to biologically relevant trideoxypropionate building blocks in optically pure form has been developed. On the basis of a three-step sequence comprising a thermal oxy-Cope rearrangement,
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.
Enantioselective decarboxylative alkylation reactions: Catalyst development, substrate scope, and mechanistic studies
Behenna, Douglas C.,Mohr, Justin T.,Sherden, Nathaniel H.,Marinescu, Smaranda C.,Harned, Andrew M.,Tani, Kousuke,Seto, Masaki,Ma, Sandy,Novak, Zoltan,Krout, Michael R.,McFadden, Ryan M.,Roizen, Jennifer L.,Enquist Jr., John A.,White, David E.,Levine, Samantha R.,Petrova, Krastina V.,Iwashita, Akihiko,Virgil, Scott C.,Stoltz, Brian M.
, p. 14199 - 14223 (2012/02/01)
α-Quaternary ketones are accessed through novel enantioselective alkylations of allyl and propargyl electrophiles by unstabilized prochiral enolate nucleophiles in the presence of palladium complexes with various phosphinooxazoline (PHOX) ligands. Excellent yields and high enantiomeric excesses are obtained from three classes of enolate precursor: enol carbonates, enol silanes, and racemic β-ketoesters. Each of these substrate classes functions with nearly identical efficiency in terms of yield and enantioselectivity. Catalyst discovery and development, the optimization of reaction conditions, the exploration of reaction scope, and applications in target-directed synthesis are reported. Experimental observations suggest that these alkylation reactions occur through an unusual inner-sphere mechanism involving binding of the prochiral enolate nucleophile directly to the palladium center. Sly as a PHOX: The development of an enantioselective decarboxylative palladium-catalyzed allylic alkylation reaction, utilizing phosphinooxazoline ligands, is described. The catalyst is applied to a range of allyl enol carbonate, silyl enol ether, and allyl β-ketoester substrates to provide alkylated ketone products in excellent yield and good ee (see scheme). The utility of these products is demonstrated by their use in several asymmetric syntheses. Mechanistic studies are reported suggesting an unusual inner-sphere mechanism. Copyright
Asymmetric palladium-catalyzed intramolecular α-arylation of aldehydes
Garcia-Fortanet, Jorge,Buchwald, Stephen L.
supporting information; experimental part, p. 8108 - 8111 (2009/04/13)
(Chemical Equation Presented) Phoxy ligand: The first catalytic method for the asymmetric palladium-catalyzed intramolecular α-arylation of α-branched aldehydes was developed (see scheme). This process is distinguished by the high yields and enantioselectivities that can be obtained, making this protocol a useful synthetic tool for further applications.
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.
A facile and modular synthesis of phosphinooxazoline ligands
Tani, Kousuke,Behenna, Douglas C.,McFadden, Ryan M.,Stoltz, Brian M.
, p. 2529 - 2531 (2008/02/05)
The copper(I) iodide catalyzed phosphine/aryl halide coupling procedure of Buchwald et al. provides modular, robust, and scaleable access to phosphinooxazoline (PHOX) ligands. The advantages of this method are highlighted by the convenient synthesis of PH
