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Research describes a higly enantioselective photocyclization conversion of amides to beta-lactams employing host-guest interaction in chiral crystals. X-ray diffraction analyses of the crystals are presented.

Research was conducted to determine the enantioselective reaction of N-methyl-N-phenyl-3-amino-2-cyclohexen-1-one derivatives to the corresponding N-methylhexahydro-4-carbazolones. The photocyclization reaction was tested in a water suspension of 1:1 inclusion compounds of the starting material consisting of optically active host compounds obtained from tartaric acid. Results indicate that the cyclohexenone and phenyl groups of the reactant exist in distant and close positions, respectively, in the two inclusion compounds.

Enantioselective photocyclization of N-alkylfuran-2-carboxyanilides to trans-dihydrofuran derivatives was examined in inclusion crystals with optically active hose compounds derived from tartaric acid. X-ray structural analysis of inclusion crysals was used to study the mechanism of the enantioselective reaction of achiral compounds in inclusion crystals. The results suggested that in some cases, the steric course of the photoreaction vary depending on the types of preparation of inclusion crystals.

A study was conducted to characterize the formation of a chiral crystal in the title oxoamide and the photochemical alteration of the chiral crystal to optically active beta-lactam. Continuous measurement of CD spectra were carried out to determine dynamic molecular behaviors in the solid state. Results indicated that glyoxylamide supports the formation of a chiral crystal with achiral molecules arranged in a chiral form.

The absolute aysmmetric synthesis of a chiral crystal formed from an achiral molecule is a topic of organic solid state chemistry. A series of two-component crystals where diphenylacetic acid is mixed with aza aromatic compounds, leading to the further formation of another chiral bimolecular crystal with phenanthridine is reported. Solid-state circular dichroism spectrometry is used for chiral discrimination.

A high accuracy universal polarimeter (HAUP)-based method was utilized to characterize the optical activity of oxo amide crystals which can be transformed photochemically to optically active beta-lactams. HAUP analysis of the oxo amide crystals indicated the presence of constant optical activity in both the reactant and the resulting product during the process of photocyclization. The components of the gyration tensor and birefringence were also negative and were not altered during the formation of (-) and (+)-beta-lactams.

The photocyclization of 2-phenylthio-3,5,5-trimethylcyclohexen-1-one to its dihydrobenzothiophene analogue and of 2-arylthio-3-methylcyclohexen-1-ones to the dihydrobenzothiophenes was carried out in inclusion compounds with optically active host molecules. The experiments yielded crystalline products with a substituent at the ortho site of the benzene ring. The high enantioselectivities achieved were attributed to the intermolecular interactions between host and guest molecules which controlled the conformation of the guest molecule.

Photolysis of furan-2-carboxanilide and N-methylfuran-2-carboxanilide in an inclusion complex with the title chiral host compound successfully produced optically active rac-trans-dihydrofuran derivatives as the sole isolable product. It is the first report of a product chirality control using only one enantiomer of a host compound. Using the title (R,R)-(-)-chiral host compound, either optically pure (-)-rac-trans-dihydrofuran or (+)-rac-trans-dihydrofuran can also be easily obtained.

Describes the photoirradiation of inclusion crystals of 2-[N-(2-propenyl)amino]cyclohex-2-enones. Preparation of inclusion compounds; Photocyclization; Optical resolution; Determination of optical purity.

Reports on the first product chirality control employing one enantiomer of a host compound. Convenience of the procedure; Inclusion complexation; Photoreaction conditions.

Novel dendralene type cross-conjugate molecules based on 1,3-dithiol-2-ylidene units with thiophene have been prepared. The conjugation in the oxidized stage is mainly through the thiophene core, while the cross-conjugated nature is observed in the neutral state. The CT complex of 2a with TCNQF4 shows moderated electrical conductivity of 10-4 S cm-1. [ABSTRACT FROM AUTHOR]

In the title compound, C28H32N6O6·2C2H6OS, the host mol­ecules are linked by N—H⋯N hydrogen bonds at both of the terminal amide groups, forming zigzag chains along the [01 ] direction. Two di­methyl sulfoxide mol­ecules are connected to a host mol­ecule by N—H⋯O hydrogen bonds. [ABSTRACT FROM AUTHOR]

The title compound [systematic name: 2-([1,1'-biphen-yl]-4-yl)-2-oxo- N , N -bis(propan-2-yl)acetamide], C 20 H 23 NO 2 was synthesized and its photoreactive properties in the crystalline state and in aceto-nitrile solution were investigated. The compound crystallizes in the chiral space group P 2 1 2 1 2 1 . The crystal does not react under UV light irradiation, perhaps due to the presence of the biphenyl group. However, the compound is photoreactive in aceto-nitrile solution to give racemic 3-( p -phenyl-phen-yl)-3-hy-droxy- N -isopropyl-4,4-di-methyl-azetidin-2-one., (© Miyamoto and Takahashi 2021.)

The title compound [systematic name: 2-oxo- N ,2-diphenyl- N -(propan-2-yl)acetamide], C 17 H 17 NO 2 , was synthesized and its photoreactive properties in the crystalline state were investigated. In the mol-ecule, the carbonyl group attached to the phenyl ring adopts an s - trans configuration with respect to the isopropyl group. Moreover, the distance between the C atom of the carbonyl group and the N-bound C atom of the isopropyl group is 3.845 (2) Å, which is much longer than 3.2 Å, the threshold for photoreactions to take place in the mol-ecule. As a result, the crystal did not photoreact upon UV light irradiation. In the crystal, the mol-ecules are linked via weak inter-molecular C-H⋯O hydrogen bonds, forming a layer structure parallel to the ab plane.