The present invention relates to methods for slowing deactivation of a catalyst and/or slowing tetraphosphine ligand usage in a hydroformylation process. In one aspect, a method comprises (a) contacting an olefin with carbon monoxide, hydrogen and a catalyst, the catalyst comprising (A) a transition metal, (B) a tetraphosphine having the structure described herein, and, optionally, (C) a monophosphine having the structure described herein, the contacting conducted in one or more reaction zones and at hydroformylation conditions; and (b) adding additional monophosphine having the structure described herein to a reaction zone.

An oxo-nitrogenated iron complex having general formula (I) or (II) wherein: R.sub.1 and R.sub.2 identical or different, represent a hydrogen atom; or are selected from linear or branched, optionally halogenated C.sub.1-C.sub.20, preferably C.sub.1-C.sub.15, alkyl groups, optionally substituted cycloalkyl groups, optionally substituted aryl groups; R.sub.3, identical or different, represent a hydrogen atom; or are selected from linear or branched, optionally halogenated C.sub.1-C.sub.20, preferably C.sub.1-C.sub.15, alkyl groups, optionally substituted cycloalkyl groups, optionally substituted aryl groups; X.sub.1 and X.sub.2, identical or different, represent a halogen atom such as, for example, chlorine, bromine, iodine; or are selected from linear or branched C.sub.1-C.sub.20, preferably C.sub.1-C.sub.15, alkyl groups, —OCOR.sub.4 groups or —OR.sub.4 groups wherein R.sub.4 is selected from linear or branched C.sub.1-C.sub.20, preferably C.sub.1-C.sub.15, alkyl groups. Said oxo-nitrogenated iron complex having general formula (I) or (II) can be advantageously used in a catalytic system for the (co)polymerization of conjugated dienes.

An oxo-nitrogenated iron complex having general formula (I) or (II) wherein: R.sub.1 and R.sub.2 identical or different, represent a hydrogen atom; or are selected from linear or branched, optionally halogenated C.sub.1-C.sub.20, preferably C.sub.1-C.sub.15, alkyl groups, optionally substituted cycloalkyl groups, optionally substituted aryl groups; R.sub.3, identical or different, represent a hydrogen atom; or are selected from linear or branched, optionally halogenated C.sub.1-C.sub.20, preferably C.sub.1-C.sub.15, alkyl groups, optionally substituted cycloalkyl groups, optionally substituted aryl groups; X.sub.1 and X.sub.2, identical or different, represent a halogen atom such as, for example, chlorine, bromine, iodine; or are selected from linear or branched C.sub.1-C.sub.20, preferably C.sub.1-C.sub.15, alkyl groups, —OCOR.sub.4 groups or —OR.sub.4 groups wherein R.sub.4 is selected from linear or branched C.sub.1-C.sub.20, preferably C.sub.1-C.sub.15, alkyl groups. Said oxo-nitrogenated iron complex having general formula (I) or (II) can be advantageously used in a catalytic system for the (co)polymerization of conjugated dienes.

A cyclopropanation method includes reacting an alcohol, an ester, or an aldehyde with a sulfone in an organic solvent containing a base providing a counter cation to form a cyclopropane; and isolating the cyclopropane. When using the alcohol or ester, the organic solvent further contains a catalyst having an alcohol dehydrogenation activity.

A cyclopropanation method includes reacting an alcohol, an ester, or an aldehyde with a sulfone in an organic solvent containing a base providing a counter cation to form a cyclopropane; and isolating the cyclopropane. When using the alcohol or ester, the organic solvent further contains a catalyst having an alcohol dehydrogenation activity.

A transition metal-based heterogeneous carbonylation reaction catalyst has an excellent catalytic activity and selectivity in the carbonylation reaction and is easily separated from a product, by crosslinking polymerizing a transition metal-based homogeneous catalyst unit through a Friedel-Craft reaction. The catalyst may be used in a method for preparing lactone. The transition metal-based heterogeneous carbonylation reaction catalyst allows to produce lactone or succinic anhydride with an epoxide compound while showing a high selectivity, and can be applied in industrial very usefully due to easy separation from the product and thus reusing thereof.

The present invention relates to a transition metal-based heterogeneous carbonylation reaction catalyst that has an excellent catalytic activity and selectivity in the carbonylation reaction and is easily separated from a product, by crosslinking polymerizing a transition metal-based homogeneous catalyst unit through a Friedel-Craft reaction; and a method for preparing lactone using the same. The transition metal-based heterogeneous carbonylation reaction catalyst allows to produce lactone or succinic anhydride with an epoxide compound while showing a high selectivity, and can be applied in industrial very usefully due to easy separation from the product and thus reusing thereof.

A method of preparing 3(4),8(9)-bisformyltricyclo[5.2.1.0.sup.2,6]decane is provided. According to the present invention, 3(4),8(9)-bisformyltricyclo[5.2.1.0.sup.2,6]decane (TCDDA) may be prepared with a high conversion rate and purity without a separate catalyst recovery process.

Provided is a carbon dioxide reduction composite catalyst, comprising an organic-inorganic porous body, and a molecular reduction catalyst combined with the organic-inorganic porous body, wherein the organic-inorganic porous body includes metal oxide clusters, and a light-condensing organic material as linkers between the metal oxide clusters, and the linkers absorb visible light to form excitons, and move the excitons through energy transfer between the linkers to transfer the electrons of the excitons to the molecular reduction catalyst.

Disclosed is a process for preparing 2,2,4,4-tetramethylcyclobutane-1,3-diol by reacting 2,2,4,4-tetramethylcyclobutane dione with isobutanol in the presence of a tandem transfer hydrogenation and Tischenko reaction catalyst.