Aza-Reformatsky-type reaction of alpha-iodomethyl ketone O-alkyl oximes promoted by titanium tetraiodide

Titanium tetraiodide promotes an aza-Reformatsky-type reaction of alpha-iodomethyl ketone O-alkyl oximes with carbonyl compounds to give beta-hydroxy ketone O-alkyl oximes in good to high yields.     

In- or in(I)-employed diastereoselective Reformatsky-type reactions with ketones: 1H NMR investigations on the active species

An efficient In- or In(I)-based stereoselective C-C bond formation is reported; the diastereoselective Reformatsky-type reactions of ketones. The predominant formations of anti isomers, confirmed by the X-ray structure analyses of ester derivatives of respective alcohols 9a(1)() and 13a(1)(), conclusively revealed the stereochemistry of the reaction path. (1)H NMR investigations revealed the formation of two types of alpha-metalated transient species from alpha-halo esters with In or In(I) halides. [reaction: see text]     

Hydrolysis of alkenyl esters and ethers catalyzed by metal complexes

[reaction: see text] Various kinds of transition metals catalyzed the hydrolysis of alkenyl esters and ethers under buffer-free, high concentration conditions compared to usual biocatalysts. Hydrolytic kinetic resolution of cis-2-tert-butylcyclohexyl vinyl ether was achieved by chiral (salen)Co complexes with good selectivity (k(rel) = 10.0).     

Reaction-phase-selective inter- and intramolecular photochemical reaction of 2-pyridone derivatives

Phase-selective photochemical reaction of 2-pyridone derivatives was examined. Irradiation of 1 in benzene mainly gave rearrangement products 2. However, intermolecular [4 + 4] photocycloaddition proceeded quantitatively in the solid state, affording photodimers 3. An effective pi-pi stacking and dipole-dipole interaction between two pyridone moieties might play important roles in an effective arrangement of 1 for photodimerization in their crystal structures. [reaction: see text]     

Formaldehyde encapsulated in zeolite: a long-lived, highly activated one-carbon electrophile to carbonyl-ene reactions

Gaseous formaldehyde is extremely unstable and readily undergoes self-polymerization to a solid paraformaldehyde or disproportionation to methanol and formic acid in the presence of moisture. We disclose a simple method to stably store such a labile formaldehyde as a monomer in a nanoporous faujasite zeolite at 5 degrees C for at least 50 days without self-polymerization or disproportionation. The greater stability of formaldehyde encapsulated in zeolite was confirmed by 13C MAS NMR spectroscopy. Formaldehyde was not only stabilized within the zeolite cages but functioned as a powerful electrophile toward various olefins. Zeolite-encapsulated formaldehyde was proved to be a stable but highly reactive C1 reagent.     

Synthesis of chiral sulfinyl-substituted 1-indolyl enones and asymmetric conjugate addition by an arylcopper reagent

The asymmetric conjugate addition of arylcopper reagents to chiral 1-[2-(p-tolylsulfinyl)]indolyl and 1-[3-(p-tolylsulfinyl)]indolyl enones was examined. With the 2-sulfinyl-indolyl derivatives, the reaction of the arylcopper reagent gave high diastereoselectivities (81-88% de's) to afford the adducts in excellent yields, although the similar addition reaction of the 3-sulfinyl derivatives afforded poor diastereoselectivities.     

A new redox-active coordination polymer with cobalticinium dicarboxylate

A new two-dimensional coordination polymer with cobalticinium 1,1'-dicarboxylate (ccdc) incorporated in the framework has been prepared, the ccdc functioning as unique monoanionic dicarboxylate ligands. The compound shows a high redox activity based on the ccdc units.     

Ion exchange at a surface monolayer

Total reflection total conversion electron yield X-ray absorption fine structure is applied to the evaluation of ion exchange occurring at the surface monolayer of two-tailed ammonium ions. X-ray absorption measurements at a Br K-edge allow us to detect ion-exchange equilibria between Br- and Cl- added in a subphase. The ion-exchange selectivity of Br- over Cl- basically increases as the monolayer is compressed, indicating that Cl- is selectively squeezed out by compression because of its larger hydrated ionic radius.