NOPR Collection: Special Issue on Complex Chemical Systems (Guest Editors: Prof. Alexander Heckel & Prof. Sandeep Verma)

Synthesis, characterization and crystal structure of 2-((4-bromophenyl) carbamoyl) phenylselenenyl bromide derived from oxidative addition of bromine to 2-phenyl-1,2-benzoisoselenazol-3-(2H)-one

Sat, 03 Aug 2013 10:57:48 GMT

Title: Synthesis, characterization and crystal structure of 2-((4-bromophenyl) carbamoyl) phenylselenenyl bromide derived from oxidative addition of bromine to 2-phenyl-1,2-benzoisoselenazol-3-(2H)-one Authors: Balkrishna, Shah Jaimin; Kumar, Amit; Panini, Piyush; Kumar, Shailesh; Kumar, Sangit Abstract: Oxidative addition of elemental bromine to 2-phenyl-1, 2-benzoisoselenazol-3-(2H)-one has been studied. Reaction of bromine with selenazolone gives the corresponding 2-phenyl-1,2-benzoisoselenazol-3-(2H)-one(IV) dibromide, which slowly rearranges to 2-((4-bromophenyl)carbamoyl)phenylselenenyl bromide when kept for crystallization for a longer period of time (24 days). Molecular conformation of the selenenyl bromide is found to be stabilized due to the presence of an intramolecular Se…O interaction along with the weak C-H…O and C-H…Br hydrogen bonds. The nature of the intramolecular Se…O interaction in selenenyl bromide has been studied by multi-nuclear (¹H, ¹³C, and ⁷⁷Se) NMR spectroscopy. Page(s): 1078-1085

One-step synthesis of 3-formyl-2-furylcarbinols and elaboration to unprecedented furotropones

Sat, 03 Aug 2013 10:57:01 GMT

Title: One-step synthesis of 3-formyl-2-furylcarbinols and elaboration to unprecedented furotropones Authors: Dhiman, Seema; Ramasastry, S S V Abstract: A general and unprecedented strategy for the synthesis of furo[2,3-d]tropone system via regioselective directed a-lithiation-alkylation and serendipitous base-promoted cyclization reaction, as key steps, has been developed. Directed a-lithiation of furan/thiophene-3-carboxaldehydes in their masked form and subsequent reaction with aldehydes efficiently provided in one-step, access to 3-formyl-2-furyl/thiophenylcarbinols, which are otherwise only accessible with difficulty. The 3-formyl-2-furylcarbinols are further elaborated to the synthesis of furo[2,3-d]tropones (also known as cyclohepta[b]furan-6-ones or furotropones) in good yields via sequential bismuth(III)chloride-catalyzed furfurylation and a novel base promoted cyclization reaction. This paper describes the general approach to the synthesis of 3-formyl-2-furylcarbinols and furotropones which could find potential applications in the synthesis of several bioactive natural products and pharmaceutics. Page(s): 1103-1112

Ferrocene-appended anionic N-heterocyclic carbene and its complex with silver(I): Synthesis, structure and catalytic evaluation

Thu, 01 Aug 2013 00:00:00 GMT

Title: Ferrocene-appended anionic N-heterocyclic carbene and its complex with silver(I): Synthesis, structure and catalytic evaluation Authors: Sarbajna, Abir; Sadhukhan, Nabanita; Saha, Sayantani; Bera, Jitendra K Abstract: A binuclear Ag(I) complex (1) bridged by two anionic N-heterocyclic carbene (NHC) ligands ferrocenoyl(1-mesityl-imidazol-2-ylidine-3-yl)amide is synthesized. X-ray structure reveals a [Ag···Ag] core spanned by two ligands, each bridging two metals through carbene carbon and amido nitrogen. The neutral complex (1) is highly soluble in a variety of organic solvents and is thermally stable. Complex (1) efficiently catalyses aniline-mediated synthesis of substituted quinolines from 2-aminobenzaldehyde and terminal alkynes. Page(s): 1072-1077

Organostannoxane-supported Pd(0) nanoparticles as an efficient catalytic system for alkyne dimerization

Sat, 03 Aug 2013 10:55:27 GMT

Title: Organostannoxane-supported Pd(0) nanoparticles as an efficient catalytic system for alkyne dimerization Authors: Chandrasekhar, Vadapalli; Narayanan, Ramakirushnan Suriya Abstract: An organostannoxane cage, [n-BuSn(O)OC(O)R]₆ [R = -C₆H₄-p-PPh₂] (SnP), has been utilised to stabilise palladium(0) nanoparticles (SnPPd). The latter is shown to efficiently catalyse the alkyne dimerisation reactions under mild reaction conditions. Page(s): 1066-1071