148461-16-9Relevant academic research and scientific papers
Phosphination of Phenol Derivatives and Applications to Divergent Synthesis of Phosphine Ligands
Li, Chenchen,Zhang, Kezhuo,Zhang, Minghao,Zhang, Wu,Zhao, Wanxiang
supporting information, p. 8766 - 8771 (2021/11/20)
We describe a general and efficient protocol for the synthesis of organophosphine compounds from phenols and phosphines (R2PH) via a metal-free C-O bond cleavage and C-P bond formation process. This approach exhibits broad substrate scope and excellent functional group tolerance. The synthetic utilities of this protocol were demonstrated by the synthesis of chiral ligands via the various transformations of cyano groups and their applications in asymmetric catalysis.
Cu/Picolinamides-Catalyzed Coupling of (Hetero)aryl Halides with Secondary Phosphine Oxides and Phosphite?
Fang, Chao,Wei, Bangguo,Ma, Dawei
supporting information, p. 2957 - 2961 (2021/08/23)
Some 4-hydroxy-picolinic acid derived amides were revealed as more efficient ligands for Cu-catalyzed coupling of (hetero)aryl halides with secondary phosphine oxides and phosphites. Only 3—5 mol% CuI and ligands were required to ensure coupling with a number of (hetero)aryl bromides and iodides to complete at 120 oC in 10—20 h.
Synthesis of N,P-, S,P-, P,P- and S,P,S-ligands using reactions of cyclopalladated complexes with KPPh2
Korte, Nicholas J.,Stepanova, Valeria A.,Smoliakova, Irina P.
, p. 356 - 362 (2013/10/01)
Readily available air- and moisture-stable dimeric chloro-bridged CN-, CS- and CP-cyclopalladated complexes with the (sp2)C-Pd bond react with 4.5 equiv. of KPPh2 in THF to give the corresponding P,N-, P,S- and P,P-bidentate ligands
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.
supporting information; experimental part, 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
Highly efficient synthesis of (Phosphinodihydrooxazole)- (1,5-cyclooctadiene) Iridium complexes
Semeniuchenko, Volodymyr,Khilya, Volodymyr,Groth, Ulrich
experimental part, p. 1147 - 1158 (2010/03/02)
A highly efficient one-pot procedure for the synthesis of complexes of the type [Ir(COD)(Phox)]X, where Phox is a (chiral) phosphinooxazoline ligand, X = PF6 or B[(3,5-(CF3)2C6H 3)]4 (BARF), is developed. Former reported syntheses demanded the isolation of pure ligands by column chromatography, but the ligands tend to adsorb irreversibly on silica. Moreover, the chromatography has to be performed with careful exclusion of air. The present method avoids this difficulties. The yields of the syntheses are comparable with those starting from the pure ligands. The method is also suitable for the preparation of complexes of the type [Rh(COD)(Phox)]BARF and [Rh(Phox)2]BARF.
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
The enantioselective Tsuji allylation
Behenna, Douglas C.,Stoltz, Brian M.
, p. 15044 - 15045 (2007/10/03)
The first catalytic enantioselective examples of the Tsuji allylation using enol carbonates and enol silanes are described. The products possess a quaternary stereogenic center and are useful building blocks for synthetic chemistry. Copyright
In situ enzymatic screening (ISES) of P,N-ligands for Ni(0)-mediated asymmetric intramolecular allylic amination
Berkowitz, David B.,Shen, Weijun,Maiti, Gourhari
, p. 2845 - 2851 (2007/10/03)
An in situ enzymatic screening (ISES) approach to rapid catalyst evaluation recently pointed to Ni(0) as a new candidate transition metal for intramolecular allylic amination. This led to further exploration of chiral bidentate phosphine ligands for such transformations. Herein, a variety of P,N-ligands are examined for this Ni(0)-chemistry, using a model reaction leading into the vinylglycinol scaffold. On the one hand, an N,N-bis(2-diphenylphosphinoethyl)alkylamine ('PNP') ligand proved to be the fastest ligand yet seen for this Ni(0)-transformation. On the other, phosphinooxazoline (PHOX) ligands of the Pfaltz-Helmchen-Williams variety gave the highest enantioselectivities (up to 51% ee) among P,N-ligands examined.
Preparation of chiral phosphorus, sulfur and selenium containing 2-aryloxazolines
Peer, Markus,De Jong, Johannes C.,Kiefer, Matthias,Langer, Thomas,Rieck, Heiko,Schell, Heico,Sennhenn, Peter,Sprinz, Juergen,Steinhagen, Henning,Wiese, Burkhard,Helmchen, Guenter
, p. 7547 - 7583 (2007/10/03)
A series of enantiomerically pure 2-[2-(diarylphosphino)aryl]-oxazolines was prepared from commercially available or synthetic amino alcohols. For oxazoline formation three procedures were employed: (i) one pot condensation with a 2-halobenzoic acid (ii) ZnCl2 catalyzed condensation with a 2-halobenzonitrile, and (iii) a three step sequence via a 2-halobenzamide and a tosylate or chloride. Phosphinooxazolines containing stereogenic phosphorous were prepared by either diastereoselective nucleophilic substitution of halogenide of Ar1Ar2PCl or by nucleophilic aromatic substitution with LiPAr1Ar2. In addition, sulfur and selenium analogs were prepared.
