New and Efficient Synthesis of 1,3-Dienylphosphonates by Palladium-Catalyzed Substitution of Propargylic Esters to Diethyl Phosphite

An efficient route to the synthesis of 1,3-dienylphosphonates (1) has been developed for the first time by the substitution of propargylic esters (2) to the diethyl phosphite (3) nucleophile in the presence of Pd₂(dba)₃ · CHCl₃ (2 mol %) and 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (4 mol%). Both the alkyl and aryl 1,3-dienylphosphonates can be prepared from this transformation.

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Phosphite‐driven, [Cp*Rh(bpy)(H2O)]2+‐catalyzed reduction of nicotinamide and flavin cofactors: characterization and application to promote chemoenzymatic reduction reactions

The organometallic compound [Cp*Rh(bpy)(H₂O)]²⁺ is a versatile catalyst for the in situ regeneration of reduced nicotinamides and flavins by catalyzing the electron transfer between the cathode or formate to the oxidized cofactors and prosthetic groups. In the present contribution we demonstrate the feasibility of phosphite as an alternative source of reducing equivalents. Thus, [Cp*Rh(bpy)(H₂O)]²⁺ combines the catalytic activities of hydrogenases, formate and phosphite dehydrogenases in one catalyst. The catalytic properties of this novel regeneration approach are investigated, demonstrating that the general catalytic properties of [Cp*Rh(bpy)(H₂O)]²⁺ are preserved. The principal applicability to promote alcoholdehydrogenase‐catalyzed reduction reactions is demonstrated. Copyright © 2010 John Wiley & Sons, Ltd.     

(R)‐N,N,N‐Trimethyl‐2‐Aminobutanol‐Bis(Trifluoromethane‐Sulfon)Imidate Chiral Ionic Liquid Used as Chiral Selector in HPCE,HPLC, and CGC

Abstract

In this work, the (R)‐N,N,N‐trimethyl‐2‐aminobutanol‐bis(trifluoromethanesulfon)imidate chiral ionic liquid was first used in chromatography and exhibited a excellent chiral recognition ability in high performance capillary electrophoresis (HPCE), high performance liquid chromatography (HPLC), and capillary gas chromatography (CGC), which also showed for the first time that chrial ionic liquid was an effective chiral selector in HPCE and HPLC. The compounds that have been separated using this chiral ionic liquid at least included alcohol, amine, acid, and amino acid, et al. enantiomers. As the chiral ionic liquid can be easily synthesized from relatively inexpensive materials, it should have a great potentiality for chiral separation in chromatographic science.     

Trimethyl borate/magnesium halide complex-induced one-pot homologation reactions of isoquinoline with dialkyl-TMP-zincate

Novel one-pot homologation reactions of isoquinoline with lithium dialkyl-TMP-zincate⋅2MgBrCl/trimethyl borate are described. 1-Alkylisoquinolines (2, 3A, 4A, 5A, 6, and 7) and 1-alkyl-3,4-dihydroisoquinolines (3B, 4B, and 5B) are easily prepared under the presented reaction conditions. The role of the B(OMe)₃/MgBrCl complex is examined in these homologation reactions. The specific reaction mechanisms, including 1,2-migration of the alkyl ligands from 1-isoquinolylzincates, are proposed. The migratory aptitudes of ligands of 1-isoquinolylzincates are also discussed.     

Synthesis and characterization of a new open-framework zinc phosphite (4,4′-(C5H4N)2(CH2)3)·[Zn3(HPO3)4]

Employing 4,4-trimethylenedipyridine as a template,a new two-dimensional zinc phosphite (4,4-(C5H4N)2(CH2)3)· [Zn3(HPO3)4 ] has been prepared at room temperature and characterized by single-crystal X-ray diffraction,FTIR,elemental analysis,powder X-ray diffraction,and thermogravimetric analysis.The compound crystallizes in the monoclinic space group P2 1 /c,with cell parameters,a=9.3309(19),b=14.798(3),c=33.637(7),β=91.11(3),V=4643.8(16) nm 3 and Z=4.The connectivity of the ZnO4 tetrahedra and HPO 3 pseudo pyramids results in infinite corner-sharing 4-membered ring chains as second building units which are further linked by Zn O P bonds to form a 2-D layer that with interesting 8-membered ring channels along the [100] direction.The diprotonated 4,4-trimethylenedipyridine molecules sit in the middle of the layers along the [100] direction and interact with the framework via hydrogen bonds.     

The use of an ionic liquid in asymmetric catalytic allylic amination

Asymmetric amination of 1,3-diphenyl-2-propenyl acetate with di-n-propylamine catalysed by palladium/P^∗-chiral diamidophosphites was carried out in ionic liquid, THF and CH₂Cl₂ with up to 90% ee. The catalyst can be reused three times without loss in enantioselectivity.     

Transformations of electrophilic reagents in a diethyl phosphite-potassium carbonate-ethanol system

Transformations of alkyl halides, aldehydes, and activated alkenes in a (EtO)₂PHO−K₂CO₃−EtOH heterophase system were studied. The reactions are catalyzed by EtOK that formed and follow the known schemes of the interaction of hydrophosphoryl compounds with electrophiles. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 369–372, February, 1999.     

Reaction of Triethyl Phosphite with Boron Tribromide

Summary.  Reaction of boron tribromide with triethyl phosphite led to the formation of triethyl tribromoborophosphate 1, a complex bearing a P→B bond. Received November 19, 1999. Accepted (revised) January 21, 2000     

Heteropolyacids enhanced the catalytic activity of Rh6(CO)16 in the hydroformylation of alkenes

Active homogeneous catalytic systems based on Rh₆(CO)₁₆‐heteropolyacids for the regioselective hydroformylation of styrene and 1‐octene and their derivatives have been developed. The effects of the amount and the type of the heteropolyacid have been studied and showed a significant improvement of the conversion of styrene and the selectivity towards branched aldehydes. Other rhodium complexes were also considered in the study and the results showed the advantages of the rhodium cluster Rh₆(CO)₁₆ associated with the heteropolyacid H₃PW₁₂O₄₀,25H₂O (HPA‐W₁₂). The effects of temperature, type of solvent and CO/H₂ pressure have also been considered in order to optimize the reaction conditions. Copyright © 2004 John Wiley & Sons, Ltd.