摘要:
The present invention relates to copper-catalyzed carbon-heteroatom and carbon-carbon bond-forming methods. In certain embodiments, the present invention relates to copper-catalyzed methods of forming a carbon-nitrogen bond between the nitrogen atom of an amide or amine moiety and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. In additional embodiments, the present invention relates to copper-catalyzed methods of forming a carbon-nitrogen bond between a nitrogen atom of an acyl hydrazine and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. In other embodiments, the present invention relates to copper-catalyzed methods of forming a carbon-nitrogen bond between the nitrogen atom of a nitrogen-containing heteroaromatic, e.g., indole, pyrazole, and indazole, and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. In certain embodiments, the present invention relates to copper-catalyzed methods of forming a carbon-oxygen bond between the oxygen atom of an alcohol and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. The present invention also relates to copper-catalyzed methods of forming a carbon-carbon bond between a reactant comprising a nucleophilic carbon atom, e.g., an enolate or malonate anion, and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. Importantly, all the methods of the present invention are relatively inexpensive to practice due to the low cost of the copper comprised by the catalysts.
摘要:
One aspect of the present invention relates to optionally substituted halogenated benzyl halides and the like. These compounds are useful as halogenated benzyl ether-based protecting groups for a variety of functional groups. Another aspect of the present invention relates to use of said protecting groups in an orthogonal protecting group strategy for the synthesis of complex molecules that comprise a number of suitable functional groups. Another aspect of the present invention relates to saccharides bearing various arrays of protecting groups of the present invention. Another aspect of the present invention relates to a method of synthesizing an oligosaccharide or glycoconjugate, comprising the steps of: using a saccharide bearing at least one protecting group of the present invention to glycosylate a second molecule to give a product comprising said saccharide; and removing a protecting group of the present invention from said product.
摘要:
Replacement solvents for use in chemical synthesis include polymer-immobilized solvents having a flexible polymer backbone and a plurality of pendant groups attached onto the polymer backbone, the pendant groups comprising a flexible linking unit bound to the polymer backbone and to a terminal solvating moiety. The polymer-immobilized solvent may be dissolved in a benign medium. Replacement solvents for chemical reactions for which tetrahydrofuran or diethyl may be a solvent include substituted tetrahydrofurfuryl ethers and substituted tetrahydro-3-furan ethers. The replacement solvents may be readily recovered from the reaction train using conventional methods.
摘要:
A method for preparing an aryl ether compound is provided in which an alcohol is reacted with an aromatic compound in the presence of a base, and a transition metal catalyst selected from the group consisting of platinum and nickel to form an aryl ether. The aromatic compound comprises an activated substituent, X, said activated substituent being a moiety such that its conjugate acid HX has a pKa of less than 5.0. The catalyst is preferably a soluble palladium complex in the presence of supporting ligands.
摘要:
A method for preparing an aryl ether compound is provided in which an alcohol is reacted with an aromatic compound in the presence of a base, and a transition metal catalyst selected from the group consisting of platinum and nickel to form an aryl ether. The aromatic compound comprises an activated substituent, X, said activated substituent being a moiety such that its conjugate acid HX has a pKa of less than 5.0. The catalyst is preferably a soluble palladium complex in the presence of supporting ligands.
摘要:
A catalytic asymmetric reduction process, which, by hydrogenating trisubstituted olefins, yields a corresponding organic compound having a high level of enantiomeric purity is disclosed. The process is also effective for the catalytic asymmetric reduction of certain enamines and related compounds to yield a corresponding amine or related compound, respectively, having a high level of enantiomeric purity. The reduction process utilizes a chiral metal catalyst that includes a metal or metal complex that is selected from groups 3, 4, 5, or 6, lanthanides and actinides. Moreover, the process uses hydrogen as the stoichiometric reducing agent and may be carried out at pressures ranging from about 0.5 to 200 atmospheres. The reaction can also be carried out using an acidic compound as a rate enhancing additive.
摘要:
A catalytic asymmetric reduction process, which, by hydrogenating enamines, yields a corresponding amine having a high level of enantiomeric purity is disclosed. The reduction process utilizes a chiral metal catalyst that includes a metal or metal complex that is selected from groups 3, 4, 5, or 6, lanthanides and actinides. Moreover, the process uses hydrogen as the stoichiometric reducing agent and may be carried out at pressures ranging from about 0.5 to 200 atmospheres.
摘要:
A process is provided for the catalytic asymmetric reduction of ketones to provide alcohol reaction products which are enriched in one enantiomer. The asymmetric reduction is accomplished utilizing an achiral metal precatalyst in combination with an optically active additive.