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C Copéret

Publications and source records attributed to C Copéret.

6 recordsLinked to original sources
PubMed2001

Olefin epoxidation with bis(trimethylsilyl) peroxide catalyzed by inorganic oxorhenium derivatives. Controlled release of hydrogen peroxide.

The replacement of organometallic rhenium species (e.g., CH(3)ReO(3)) by less expensive and more readily available inorganic rhenium oxides (e.g., Re(2)O(7), ReO(3)(OH), and ReO(3)) can be accomplished using bis(trimethylsilyl) peroxide (BTSP) as oxidant in place of aqueous H(2)O(2). Using a catalytic amount of a proton source, controlled release of hydrogen peroxide helps preserve sensitive peroxorhenium species and enables catalytic turnover to take place. Systematic investigation of the oxorhenium catalyst precursors, substrate scope, and effects of various additives on olefin epoxidation with BTSP are reported in this contribution.

Alkenes↗
PubMed2000

Efficient epoxidation of alkenes with aqueous hydrogen peroxide catalyzed by methyltrioxorhenium and 3-cyanopyridine.

The epoxidation of alkenes with 30% aqueous hydrogen peroxide is catalyzed efficiently by methyltrioxorhenium (MTO) in the presence of pyridine additives. The addition of 1-10 mol % of 3-cyanopyridine increases the system's efficiency for terminal and trans-disubstituted alkenes resulting in high isolated yields of the corresponding epoxides. The system allows for epoxidation of alkenes with various functional groups. Alkenes leading to acid-sensitive products are efficiently epoxidized using a mixture of pyridine and 3-cyanopyridine as additives. This method is operationally very simple and uses an environmentally benign oxidant. The effects of different pyridine additives on the alkene conversion and the catalyst lifetime are discussed.

Alkenes↗
PubMed2000

Low-Temperature Hydrogenolysis of Alkanes Catalyzed by a Silica-Supported Tantalum Hydride Complex, and Evidence for a Mechanistic Switch from Group IV to Group V Metal Surface Hydride Complexes We are grateful to Dr. L. Lefort, Dr. O. Maury (LCOMS), Dr. C. Meric de Bellefon, and Dr. D. Schweich from the laboratory LGPC (ESCPE Lyon) for fruitful discussions. We wish to thank the CNRS, and the ESCPE-Lyon for financial support. M.C. is also grateful to the French Ministry for Education, Research, and Technology (MENRT) for a predoctoral fellowship.

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Journal Article↗
PubMed1999

Palladium-catalyzed highly diastereoselective cyclic carbopalladation-carbonylative esterification tandem reaction of iododienes and iodoarylalkenes.

[formula: see text] Pd-catalyzed reaction of iododienes and iodoarylalkenes represented by 1, 8, and 10 under 1 atm of CO and a small amount of O2 in the presence of a base, e.g., NEt3, as well as MeOH and H2O in DMF can undergo a highly diastereoselective cyclic carbopalladation-carbonylative esterification tandem process (Type II C-Pd process) to give in high yields the corresponding ester-containing cyclization products, e.g., 2, 9, and 11, in as high as 98% diastereoselectivity.

Alkenes↗