Patent classifications
C07C1/321
Asymmetric addition reactions
Processes of forming C.sub.sp2C.sub.sp3 bonds at the allylic carbon of a cyclic allylic compound starting material are disclosed, in which a racemic mixture of a cyclic allylic compound having a leaving group attached to the allylic carbon is reacted with a compound having a nucleophilic carbon atom in the presence of a Rh(I), Pd(II) or Cu(I) pre-catalyst and a chiral ligand. The reaction products containing the newly-formed C.sub.sp2C.sub.sp3 bond are generated in high stereoisomeric excess, and may therefore serve as important organic building blocks in the preparation of new agrochemicals and pharmaceuticals.
SURFACE-MODIFIED CALCIUM CARBONATE AS CARRIER FOR TRANSITION METAL-BASED CATALYSTS
The present invention relates to a catalyst system comprising a transition metal compound on a solid carrier which is a surface-reacted calcium carbonate. The invention further relates to a method for manufacturing said catalyst system and to its use in heterogeneous catalysis.
SURFACE-MODIFIED CALCIUM CARBONATE AS CARRIER FOR TRANSITION METAL-BASED CATALYSTS
The present invention relates to a catalyst system comprising a transition metal compound on a solid carrier which is a surface-reacted calcium carbonate. The invention further relates to a method for manufacturing said catalyst system and to its use in heterogeneous catalysis.
POLYMER-SUPPORTED TRANSITION CATALYST
A long life catalyst is provided that is conveniently and inexpensively capable of being produced and that is highly active and has inhibited metal leakage. According to aspects of the present invention, a catalyst is provided that includes: a polymer including a plurality of first structural units and a plurality of second structural units; and metal acting as a catalytic center, wherein at least part of the metal is covered with the polymer, each of the plurality of first structural units has a first atom constituting a main chain of the polymer and a first substituent group bonded to the first atom, a second atom included in each of the plurality of second structural units is bonded to the first atom, and the second atom is different from the first atom, or at least one of all substituent groups on the second atom is different from the first substituent group.
POLYMER-SUPPORTED TRANSITION CATALYST
A long life catalyst is provided that is conveniently and inexpensively capable of being produced and that is highly active and has inhibited metal leakage. According to aspects of the present invention, a catalyst is provided that includes: a polymer including a plurality of first structural units and a plurality of second structural units; and metal acting as a catalytic center, wherein at least part of the metal is covered with the polymer, each of the plurality of first structural units has a first atom constituting a main chain of the polymer and a first substituent group bonded to the first atom, a second atom included in each of the plurality of second structural units is bonded to the first atom, and the second atom is different from the first atom, or at least one of all substituent groups on the second atom is different from the first substituent group.
Method of preparing solid-supported palladium catalyst
A solid-supported Pd catalyst is suitable for CC bond formation, e.g., via Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions, with a support that is reusable, cost-efficient, regioselective, and naturally available. Such catalysts may contain Pd nanoparticles on jute plant sticks (GS), i.e., Pd@GS, and may be formed by reducing, e.g., K.sub.2PdCl.sub.4 with NaBH.sub.4 in water, and then used this as a dip catalyst. The dip catalyst can catalyze Suzuki-Miyaura and Mizoroki-Heck cross coupling-reactions in water. The catalysts may have a homogeneous distribution of Pd nanoparticles with average dimensions, e.g., within a range of 7 to 10 nm on the solid support. Suzuki-Miyaura cross-coupling reactions may achieve conversions of, e.g., 97% with TOFs around 4692 h.sup.?1, Mizoroki-Heck reactions with conversions of, e.g., a 98% and TOFs of 237 h.sup.?1, while the same catalyst sample may be used for 7 consecutive cycles, i.e., without addition of any fresh catalyst.
Method of preparing solid-supported palladium catalyst
A solid-supported Pd catalyst is suitable for CC bond formation, e.g., via Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions, with a support that is reusable, cost-efficient, regioselective, and naturally available. Such catalysts may contain Pd nanoparticles on jute plant sticks (GS), i.e., Pd@GS, and may be formed by reducing, e.g., K.sub.2PdCl.sub.4 with NaBH.sub.4 in water, and then used this as a dip catalyst. The dip catalyst can catalyze Suzuki-Miyaura and Mizoroki-Heck cross coupling-reactions in water. The catalysts may have a homogeneous distribution of Pd nanoparticles with average dimensions, e.g., within a range of 7 to 10 nm on the solid support. Suzuki-Miyaura cross-coupling reactions may achieve conversions of, e.g., 97% with TOFs around 4692 h.sup.?1, Mizoroki-Heck reactions with conversions of, e.g., a 98% and TOFs of 237 h.sup.?1, while the same catalyst sample may be used for 7 consecutive cycles, i.e., without addition of any fresh catalyst.
PROCESS OF REACTING SILICONE WITH HYDROTHERMAL OR SUPERCRITICAL WATER
A process for reacting silicone with hydrothermal water is at temperatures from 140? C. or supercritical water. A solids mixture containing silicon is formed.
Solid-supported catalyst for cross-coupling
A solid-supported catalyst ligand which chelates palladium (II) species to form a complex that functions as a heterogeneous catalyst that is stable and can be recycled without significantly losing any catalytic activity in a variety of chemical transformations, a method for producing the solid-supported catalyst ligand and a method for catalyzing a palladium cross-coupling reaction, such as the Suzuki-Miyaura, Mizoroki-Heck, and Sonagashira reactions.
Solid-supported catalyst for cross-coupling
A solid-supported catalyst ligand which chelates palladium (II) species to form a complex that functions as a heterogeneous catalyst that is stable and can be recycled without significantly losing any catalytic activity in a variety of chemical transformations, a method for producing the solid-supported catalyst ligand and a method for catalyzing a palladium cross-coupling reaction, such as the Suzuki-Miyaura, Mizoroki-Heck, and Sonagashira reactions.