Direct Conversion of Phosphonates to Phosphine Oxides: An Improved Synthetic Route to Phosphines Including the First Synthesis of Methyl JohnPhos
作者:Alexander J. Kendall、Chase A. Salazar、Patrick F. Martino、David R. Tyler
DOI:10.1021/om500854u
日期:2014.11.10
reaction intermediate. A diverse array of phosphonates was converted to phosphine oxides using a variety of Grignard reagents for direct carbon–phosphorus functionalization. This new methodology especially simplifies the synthesis of dimethylphosphino (RPMe2)-type phosphines by using air-, water-, and silica-stable intermediates. To highlight this reaction, a new Buchwald-type ligand ([1,1′-biphenyl]-
Part I: The Development of the Catalytic Wittig Reaction
作者:Christopher J. O'Brien、Zachary S. Nixon、Andrew J. Holohan、Stephen R. Kunkel、Jennifer L. Tellez、Bryan J. Doonan、Emma E. Coyle、Florie Lavigne、Lauren J. Kang、Katherine C. Przeworski
DOI:10.1002/chem.201301444
日期:2013.11.4
developed the first catalytic (in phosphane) Wittigreaction (CWR). The utilization of an organosilane was pivotal for success as it allowed for the chemoselective reduction of a phosphane oxide. Protocol optimization evaluated the phosphane oxide precatalyst structure, loading, organosilane, temperature, solvent, and base. These studies demonstrated that to maintain viable catalytic performance it was
The treatment of triphenylphosphine oxide with organometallic reagents leads to the substitution of up to three phenyl substituents with the incoming carbon nucleophile. The replacement of the phenyl/aryl group in tertiary diarylalkylphosphine oxides or even aryldialkylphosphine oxides was also observed. Naphthyl-substituted phosphine oxides undergo Michael-type addition at the naphthyl group when
oxygen-transfer reactions proceed via 1:1 charge-transfer (CT) complexes formed between the substrates and cumylperoxyl radical. The primarykineticisotopeeffects are determined by comparing the rates of N,N-dimethylanilines and the corresponding N,N-bis(trideuteriomethyl)anilines. The isotope effect profiles are quite different from those reported for the P-450 model oxidation of the same series of substrates
CATALYSTS FOR THE PRODUCTION OF HYDROXY ETHER HYDROCARBONS BY VAPOR PHASE HYDROGENOLYSIS OF CYCLIC ACETALS AND KETALS
申请人:Devon Thomas James
公开号:US20120330067A1
公开(公告)日:2012-12-27
Catalyst compositions of palladium supported on alumina or zirconium oxide supports having low or no silicon dioxide contents and having a specific surface area or modified with alkali, alkaline earth, or phosphine oxide compounds are selective in a vapor phase hydrogenolysis reaction to convert cyclic acetal compounds and/or cyclic ketal compounds in the presence of hydrogen to their corresponding hydroxy ether hydrocarbon reaction products.