149095-48-7Relevant academic research and scientific papers
Axially Chiral Biaryl Monophosphine Oxides Enabled by Palladium/WJ-Phos-Catalyzed Asymmetric Suzuki-Miyaura Cross-coupling
Ji, Wangqin,Wu, Hai-Hong,Zhang, Junliang
, p. 1548 - 1554 (2020/02/04)
A highly enantioselective palladium/WJ-Phos-catalyzed Suzuki-Miyaura coupling reaction for efficient construction of axially chiral biaryl monophosphine oxides was developed. A series of axially chiral biaryl monophosphine oxides were obtained in good yields and with high enantioselectivities. The practicability of this reaction was validated in the straightforward synthesis of axially chiral biaryl monophosphine ligand and demonstrated by a 100-g-scale synthesis. Moreover, various functionalizations of the product make it as a platform molecule for synthesis of other chiral biaryl phosphines.
Phosphinofulvene Enolate Ligands in Ruthenium Complexes by Ferrocene Photolysis under Solar Radiation
Carrión, M. Carmen,Torres, Javier,Jalón, Félix A.,Rodríguez, Ana M.,Zirakzadeh, Afrooz,Manzano, Blanca R.
, p. 1153 - 1162 (2017/03/11)
Ruthenium complexes containing a new type of phosphine ligand were obtained through photochemical transformations. The process involves the irradiation of (phosphinoferrocenylcarbonyl)ruthenium derivatives with visible light (tungsten halogen lamp) to yield complexes with κ2-P,O phosphinofulvene enolate ligands after the formal loss of the “CpFe+” (Cp = cyclopentadienyl) entity. A tandem reaction that involves the irradiation of a mixture of a (hydroxymethyl)ferrocenylphosphine ligand and (arene)ruthenium precursors is also possible. The reaction proceeds through the coordination of the hydroxy phosphine ligands, evolution to hydrido ketone (or hydrido aldehyde) complexes and subsequent evolution to the fulvene derivatives. The process also occurs under solar radiation. The photolysis reaction was studied at different wavelengths of the visible spectrum by irradiation with light-emitting diodes (LEDs). Positive results were obtained when irradiation was performed in the wavelength region corresponding to the metal-to-ligand charge-transfer (MLCT) band that is characteristic of the acylferrocenyl moiety. The use of green light (λ = 530 nm) gave the best results, and the reaction did not proceed under higher-wavelength light or in the dark. A non-coordinated phosphinoferrocenylcarbaldehyde ligand also evolved under solar radiation, but a complex mixture was obtained; thus, the selectivity increases significantly if the ruthenium centre is present.
Internal adduct formation of active intramolecular C4-bridged frustrated phosphane/borane Lewis pairs
Wang, Xiaowu,Kehr, Gerald,Daniliuc, Constantin G.,Erker, Gerhard
supporting information, p. 3293 - 3303 (2014/03/21)
The tetramethylene-bridged PMes2/B(C6F 5)2 frustrated Lewis pair (FLP) 8 was prepared by hydroboration of Mes2P-(CH2)2CH=CH2 with HB(C6F5)2. It is an active FLP that splits dihydrogen under mild conditions and, consequently, serves as a metal-free hydrogenation catalyst for a variety of substrates. It also reacts typically with terminal acetylenes. The C4-bridged FLP 23 was prepared by HB(C6F5)2 hydroboration of 1- dimesitylphosphino-2-vinylferrocene. It represents a rare example of a FLP where the equilibrium between the open form and the closed internal P/B adduct form is experimentally observable. It also shows a variety of typical FLP reactions, including dihydrogen splitting. The FLPs 8 and 23 (open form) and many precursors and products were characterized by X-ray diffraction.
A Planar-Chiral Phosphino(alkenyl)ferrocene for Suzuki-Miyaura C-C Coupling Reactions
Schaarschmidt, Dieter,Grumbt, Martin,Hildebrandt, Alexander,Lang, Heinrich
, p. 6676 - 6685 (2016/02/19)
Planar-chiral phosphinoferrocene [Fe(η5-C5H3-1-PPh2-2-(E)-CH=CHPh)(η5-C5H5)] (4) was applied in the presence of palladium in Suzuki-Miyaura couplings for the synthesis of sterically congested biaryls. The catalytic activity arises from homogeneous palladium phosphine complexes, of which the potential pre-catalyst [Pd(4)2Cl2] was characterized structurally. The catalytic system is excellently suited for the synthesis of tri-ortho-substituted biaryls under mild conditions (0.1 mol-%, 50-100 C), whereas its application towards the synthesis of tetra-ortho-substituted biaryls is quite limited. Comparing the performance of the reaction with 4 as catalyst and a range of substrates with differing ortho substituents suggests that transmetalation is rate determining. Complex (Sp)-4 was used in atropselective couplings, wherein enantioenrichments of up to 36 % were achieved. The stereoselectivity depends to some extent on the steric properties of the boronic acids; however, slight changes at the aryl halides influence the enantioselectivity.
Desymmetrizing hydroformylation with the aid of a planar chiral catalyst-directing group
Breit, Bernhard,Breuninger, Daniel
, p. 10244 - 10245 (2007/10/03)
Desymmetrizing hydroformylation of bisalkenyl- and bisallylcarbinols could be achieved employing a chiral substrate-bound catalyst-directing group (o-DPPF) with excellent levels of diastereotopic alkene face and diastereotopic alkene group discrimination to give bifunctionalized chiral aldehydes in enantiomerically pure form. Copyright
Selective functionalization of the 1′-position in ferrocenecarbaldehyde
Iftime, Gabriel,Moreau-Bossuet, Caroline,Manoury, Eric,Balavoine, Gilbert G. A.
, p. 527 - 528 (2008/10/09)
An efficient and selective new method for the preparation of unsymmetrical 1,1′-disubstituted ferrocenes by a one-pot procedure, starting from ferrocenecarbaldehyde, is disclosed.
