A highly enantioselective amide allylation of α-iminoamides has been achieved using catalytic amounts of InCl3, ZnCl2 and a BINOL derivative. This reaction allowed facile access to a variety of amide functionalised α-methylene-γ-butyrolactams in excellent yields with high enantioselectivities.

A novel and facile synthesis of azaspiro-γ-lactones with a methylene–lactam framework from N-carbonyl imides is described. Mechanistic investigations provide evidence for a two-step reaction process involving ZnCl2-promoted addition of β-amido allylindium species followed by an unexpectedly molecular-sieves-mediated ring opening–reclosure concomitantly with the loss of an N-carbonyl unit.

New chiral C2-symmetric and unsymmetric lactam-fused pyridines have been synthesised in enantiomerically pure forms with satisfactory yields via an acid-promoted cyclisation of benzylidene-modified tetramic acids and various enamines.

This work reports an intriguing finding that a newly designed anthracene/perylene/rhodamine system makes it possible to achieve efficient cascade energy transfer. The results of comparative spectroscopic studies on the protonated compounds provided a direct proof that the perylene dye can promote gap-filling functionality as an energy transmitter to enhance overall efficiency for the energy flow.

This communication reports a significant breakthrough on the novel catalytic amide allylation to the acyclic α-ketoester systems, achieving satisfactorily high yields and extremely high levels of the asymmetric induction to allow for highly enantioselective synthesis of ester functionalised α-methylene-γ-butyrolactones.

Organocatalytic tandem reactions of L-phenylalanine-derived tetramic acid with aldehydes allow a one-pot and high-yielding access to a diverse range of novel chiral diols in enantiomerically pure forms. In addition, a new entry of the diols, featuring their unique structures associated with C2- and pseudo C2-symmetric chiral motifs, is reported.

A remarkably effective method allowing an extremely high enantioselective synthesis of the spiro-fused 2-oxindole/α-methylene-γ-butyrolactones is described. The key strategy lies in the use of indium-catalyzed asymmetric amide allylation of N-methyl isatin with functionalized allylstannanes, which can lead to the antineoplastic spirocyclic lactones in almost enantiopure forms.

The first total synthesis of antibacterial epicoccarine A isolated from a fungus Epicoccum sp. has been accomplished in 10 steps along with synthetic elaboration of its C5-epimer, highlighting the utility of O- to C-acyl rearrangement of a 4-O-acyltetramic acid derivative. Comparison of spectroscopic properties and specific optical rotations of the synthetic samples with those reported for authentic material has clearly indicated the unspecified absolute stereochemistry of this natural product to be 5S.

Synthesis of a new type of mucic acid 1,4-lactone methyl ester 3-O-ferulate related to an extractive component isolated from Citrus sudachi, and its diastereomer has been achieved by employing stereodivergent dihydroxylation as a key step. The structures of the final products are fully characterized by spectroscopic methods and compared with that of the natural product.

For the efficient approach to medicinally important α-branched 3-acyltetramic acids, the key reaction of O- to C- acyl rearrangement using α-amino-acid-derived 4-O-acyltetramic acids was extensively examined in the presence of various metal salts. Use of CaCl2 or NaI dramatically changed the results in the reaction efficiency and rapidly brought about the desired α-branched 3-acyltetramic acids in markedly improved yields. We also discuss an epimerization at C5 stereocenter under the rearrangement conditions as well as the tolerance for structural variation at C3 and C5. In addition to the preceding success in the total synthesis of new cytotoxic tetramic acid, penicillenol A1, this methodology could be also applied to the first total synthesis of penicillenol A2.

Detailed exploratory and mechanistic investigations on spontaneous formation of dye-functionalized gold nanoparticles (GNPs) using dye-based reverse micellar systems are described in this publication. The accumulated results from spectroscopic and microscopic investigations demonstrated that water molecules confined within nanoscopic enclosure of the self-assembled reverse micelles played critical role in the redox processes of aurate ions to produce GNPs, which are assumed to have approximately constant size distributions. The resulting dye-functionalized GNPs were found to offer their absorption and fluorescence emission tunability by changing the medium polarity as well as to exhibit excellent film-forming properties to give optically homogeneous polystyrene thin films. These key findings in addition to broad applicability of the self-assembling process with a variety of dye analogues have led to a conclusion that the protocol presented here serves as a versatile synthetic method to provide a potential convenience for future development of new organic–inorganic hybrid nanomaterials.Graphical abstractDetailed exploratory and mechanistic investigations on spontaneous formation of dye-functionalized gold nanoparticles using dye-based reverse micellar systems are described in this publication.Research highlights► Water molecules play a significant role for GNP formations. ► GNPs are assumed to have approximately constant size distributions. ► Photophysical property can be tuned by changing medium polarity. ► Dye-functionalized GNPs exhibit excellent film-forming properties. ► Synthetic protocol has broad applications for dye analogues.

The first total synthesis of (+)-batzellaside B and its C8-epimer was completed from a known l-arabinose-derived tribenzyl ether in 22 steps with overall yields of 3.9% and 5.4%, respectively. The absolute configuration of (+)-batzellaside B was unambiguously determined to be 1S,3S,4S,5R,8S by the Mosher analysis of a synthetic intermediate prepared through a separate route.

Construction of light-harvesting reverse micelle system was achieved in nanoscopic dimensions via self-assembly of anthracene–perylene triad which could undergo efficient intramolecular energy transfer from the anthracene antennae to the perylene cores. Absorption spectra of the reverse micelles in toluene solutions exhibited broad, unstructured, and red-shifted bands attributed to interacting chromophores within molecular aggregates, while the emission spectra showed significant fluorescence quenching of both the excited anthracene and the perylene groups. The atomic force microscope (AFM) analysis revealed a number of small and medium-sized spherical objects that can be attributed to the individual reverse micelles and their assemblies. A cross-sectional view of the AFM image indicated that nearly 90% of these peak heights were less than 10 nm. Titration experiments of fluorescence properties of the reverse micelles allowed determination of its cmc value as 3 μM. Spectroscopic and microscopic behavior of a series of the reverse micelles at the W0 values (water/surfactant ratios) of 30, 50, 100, and 200 suggested that the reverse micelles should have a uniform aggregate size independent of the water/surfactant ratio, revealing a unique relation between specific geometrical configuration of the amphiphilic molecules and intrinsic size of the reverse micelles.

A highly enantioselective amide allylation of α-iminoamides has been achieved using catalytic amounts of InCl3, ZnCl2 and a BINOL derivative. This reaction allowed facile access to a variety of amide functionalised α-methylene-γ-butyrolactams in excellent yields with high enantioselectivities.

This communication reports a significant breakthrough on the novel catalytic amide allylation to the acyclic α-ketoester systems, achieving satisfactorily high yields and extremely high levels of the asymmetric induction to allow for highly enantioselective synthesis of ester functionalised α-methylene-γ-butyrolactones.