427 results about "Olefin metathesis" patented technology

The present invention provides methods for the synthesis of catalysts and precursors thereof. Methods of the invention may comprise combining a catalyst precursor and at least one ligand to generate a catalytically active species, often under mild conditions and in high yields. In some cases, a wide variety of catalysts may be synthesized from a single catalyst precursor. Methods of the invention may also include the preparation of catalysts which, under reaction conditions known in the art, may have been difficult or impossible to prepare and / or isolate due to, for example, steric crowding at the metal center. The present invention also provides catalyst compositions, and precursors thereof, which may be useful in various chemical reactions including olefin metathesis. In some cases, methods of the invention may reduce the number of synthetic and purification steps required to produce catalysts and / or other reaction products, as well as reducing time, cost, and waste production.

Processes for producing hydrocarbons in the gasoline and jet fuel range. The processes involve the thermal decarboxylation of fatty acids, which can be derived from the hydrolysis of triglycerides, which triglycerides can be vegetable oils, animal fats, or combinations thereof. The resulting hydrocarbons can be hydrocracked, and, optionally, isomerized and / or hydrotreated, to yield hydrocarbons in the jet fuel or gasoline range. Where the resulting hydrocarbons include olefinic double bonds, they can alternatively be combined with low molecular weight olefins, and subjected to olefin metathesis to yield hydrocarbons in the jet fuel or gasoline range.

Organometallic complexes suitable as olefin metathesis catalysts are provided. The complexes are Group 8 transition metal carbenes bearing a cationic substituent and having the general structure (I)wherein M is a Group 8 transition metal, L1 and L2 are neutral electron donor ligands, X1 and X2 are anionic ligands, m is zero or 1, n is zero or 1, and R1, W, Y, and Z are as defined herein. Methods for synthesizing the complexes are also provided, as are methods for using the complexes as olefin metathesis catalysts.

The present invention relates generally to catalysts and processes for the Z-selective formation of internal olefin(s) from terminal olefin(s) via homo-metathesis reactions.

Improved catalysts useful in alkyne or olefin metathesis are made by bringing into contact a multi-coordinated metal complex comprising a multidentate Schiff base ligand, and one or more other ligands, with a selected activating compound under conditions such that at least partial cleavage of a bond between the metal and the multidentate Schiff base ligand of said metal complex occurs.

The present invention provides methods for the synthesis of catalysts and precursors thereof. Methods of the invention may comprise combining a catalyst precursor and at least one ligand to generate a catalytically active species, often under mild conditions and in high yields. In some cases, a wide variety of catalysts may be synthesized from a single catalyst precursor. Methods of the invention may also include the preparation of catalysts which, under reaction conditions known in the art, may have been difficult or impossible to prepare and / or isolate due to, for example, steric crowding at the metal center. The present invention also provides catalyst compositions, and precursors thereof, which may be useful in various chemical reactions including olefin metathesis. In some cases, methods of the invention may reduce the number of synthetic and purification steps required to produce catalysts and / or other reaction products, as well as reducing time, cost, and waste production.

The present invention provides a new type of alpha-helix nucleating cross-link (“staple”) formed by olefin metathesis of a proline derivative with an alkenyl side chain and another amino acid derivative with an alkenyl side chain. The proline derivatives as described herein have been found to be strong nucleators of alpha-helix formation. The invention also provides moieties for shielding the free amide N—H's at the N-terminus of an alpha-helix, thereby further stabilizing the helix. The proline derivatives, precursors prior to cross-linking, and the cross-linked peptides are provided as well as methods of using and preparing these compounds and peptides.