background marine sponge/nano-cuo as a natural catalyst efficiently catalyzed the sulfonylation reaction of p-chlorobenzene sulfonyl chlorides with amines in order to prepare sulfonamides. the advantages included use of a natural catalyst, ease of handling, requirement of a very small amount of catalyst, mild reaction condition and appropriateness to high yield. objectives the current study aim...

Glycoside hydrolases of families 32 (GH32) and 68 (GH68) belong to clan GH-J, containing hydrolytic enzymes (sucrose/fructans as donor substrates) and fructosyltransferases (sucrose/fructans as donor and acceptor substrates). In GH32 members, some of the sugar substrates can also function as inhibitors, this regulatory aspect further adding to the complexity in enzyme functionalities within thi...

Chiral MnIII (salen) complex supported on modified ZPS-PVPA (zirconium poly(styrenephenylvinylphosphonate)) and ZPS-IPPA (zirconium poly(styrene-isopropenyl phosphonate)) were prepared using –CH2Cl as a reactive surface modifier by a covalent grafting method. The supported catalysts showed higher chiral induction (ee: 72%–83%) compared with the corresponding homogeneous catalyst (ee: 54%) for a...

A water-soluble and air-stable Pd(NH3)2Cl2/cationic 2,2'-bipyridyl system was found to be a highly-efficient and reusable catalyst for the coupling of aryl iodides and alkenes in neat water using Bu(3)N as a base. The reaction was conducted at 140 degrees C in a sealed tube in air with a catalyst loading as low as 0.0001 mol % for the coupling of activated aryl iodides with butyl and ethyl acry...

The dTDP-glucose 4,6-dehydratase catalyzed conversion of dTDP-glucose to dTDP-4-keto-6-deoxyglucose occurs in three sequential chemical steps: dehydrogenation, dehydration, and rereduction. The enzyme contains the tightly bound coenzyme NAD(+), which mediates the dehydrogenation and rereduction steps of the reaction mechanism. In this study, we have determined that Asp135 and Glu136 are the aci...

A series of unsymmetric salen ligands derived from 1,2-diaminocyclohexane bearing an appended Lewis base on the three-position of one aromatic ring were synthesized by the reaction of various functional salicyaldehydes with the condensation product of 1,2-diaminocyclohexane mono(hydrogen chloride) and 3,5-di-tert-butylsalicylaldehyde. These ligands in conjunction with Ti(O(i)Pr)(4) exhibited ex...

The reduction of nitroarenes to anilines as well azobenzenes hydrazobenzenes using a single base-metal catalyst is reported. hydrogenation reactions are performed with an air-and moisture-stable manganese and proceed under relatively mild reaction conditions. transformation tolerates broad range functional groups, affording aniline derivatives in high yields. Mechanistic studies suggest that th...