Catalysis - Issued patents / Published patent applications

Aldehydes were obtained in excellent yields from ruthenium-porphyrin-catalyzed oxidation of various terminal alkenes with 2,6-dichloropyridine N-oxide under mild conditions. The aldehydes generated from these ruthenium-catalyzed alkene oxidation reactions can be used in-situ for olefination reactions with ethyl diazoacetate in the presence of PPh3, leading to one-pot diazoacetate olefination starting from alkenes.

The invention provides N,N'-disubstituted monothiourea or bis-thiourea-Pd(0) complexes that are useful as catalysts for palladium-catalyzed Heck reaction of aryl iodides and bromides with olefins, and as catalysts for palladium catalyzed Suzuki reactions of organoboric compounds and aryl halides.

The present invention relates to the use of nanosized metal particles (e.g., ruthenium) grafted on inert solid support for oxidation of alkenes. The supported metal catalyst can effect cis-dihydroxylation and oxidative cleavage of alkenes to give the respective cis-diols and carbonyl products.

Diastereoselective epoxidation of allylically substituted alkenes using metalloporphyrins as catalyst provides high trans-selectivities (i.e., trans-:cis-epoxide ratio). A diversity of cycloalkenes bearing different allylic substituents are shown to be efficiently epoxidized to afford the corresponding trans-epoxides with excellent trans-selectivities (up to >98%) and good yields (up to 99%). Acyclic allylic alkenes bearing different allylic substituents are efficiently epoxidized to afford the corresponding erythro-epoxides with good erythro-selectivities. The metalloporphyrin-catalyzed reactions exhibit up to 20 times higher trans-selectivities than the conventional method using m-chloroperoxybenzoic acid as oxidant.

An intramolecular amidation processes for substrates such as sulfamates using chiral and non-chiral metalloporphyrin complexes which can maximize catalytic activity, enhance efficiency, stereoselectivity and speed of amidation reactions is described. The chiral metalloporphyrin catalyzed amidation of sulfamates exhibits excellent cis-selectivity, affording cyclic sulfamidates with high enantiomeric excess values.

A general, efficient, and environmentally friendly method is provided for producing mostly beta-epoxides of delta<5>-unsaturated steroids using certain ketones as the catalyst along with an oxidizing agent, or by using certain dioxiranes. In another aspect of the invention, a method is provided for producing mostly 5beta,6beta-epoxides of steroids from delta<5>-unsaturated steroids having a substituent at the 3alpha-position by an epoxidation reaction using a ketone along with an oxidizing agent under conditions effective to generate epoxides, or using a dioxirane under conditions effective to generate epoxides.; a whole range of delta<5>-unsaturated steroids, bearing different functional groups such as hydroxy, carbonyl, acetyl or ketal group as well as different side chains, were conveniently converted to the corresponding synthetically and biologically interesting 5beta,6beta-epoxides with excellent beta-selectivities and high yields.