We have developed an iron catalyzed oxidative dimerization of pyrrolo[2,1-a]isoquinolines and pyrrolo[1,2-a]quinolines. A series of dimeric pyrrolo[2,1-a]isoquinolines and pyrrolo[1,2-a]quinolines can be prepared efficiently under mild reaction conditions with DTBP as oxidant and HFIP as solvent (19 examples, 42–76% yield).

Penta-bridged covalent bis-pillar[5]arenes have garnered significant attention recently as single-molecule nanotubular structures. In this study, we synthesized hetero-dimeric covalent-organic pillars (hetero-COPs) by coupling penta-aldehyde and penta-amine pillar[5]arene derivatives. NMR spectroscopic, mass spectrometric, and X-ray crystallographic analyses confirmed the formation of a pair of directionally asymmetrical hetero-COPs with an overall length of 1.8 nm. Furthermore, we observed social chiral sorting during the [1 + 1] imine condensation process of these macrocyclic building blocks. Although the synthetic efficiency requires further improvement, our findings provide valuable insights into the design of directional nanotubes based on bis-pillar[5]arene.

A new method is developed for efficient and chemoselective synthesis of benzo[1,4]oxazineone derivatives. By the choice of an appropriate ionic liquid, the process is directed towards selective O- or N-alkylation to give the desired isomeric structures, as the major product of the reaction. In the presence of choline hydroxide, benzo[1,4]oxazine-3-one derivatives are formed, while by using choline fluoride, the corresponding benzo[1,4]oxazine-2-ones are obtained. The latter pathway would be facilitated for sluggish reactants by in situ use of an alkyl halide.

Psidials L and M (1 and 2), two sesquiterpene-based meroterpenoids with unknown skeletons, and Psipinene (3), one novel monoterpene-based meroterpenoid, had been isolated from the leaves of Psidium guajava. Their structures were determined by spectroscopic data and calculated ECD spectra. The absolute structure of compound 1 was also determined by X-ray single crystal diffraction analysis. A plausible biosynthetic pathway for 1–2 was postulated. Compound 1 showed significant protective activity toward cisplatin-damaged HK2 cells.

We report the synthesis of diaminocyclitol, protected 1,4-trans-1,5-cis-4,5-diamino-2-cyclopenten-1-ol. The key strategy was stereoselective vinylation of an acyclic chiral α-amino aldimine to construct syn-diamine moiety. The 1,5-cis-amino alcohol moiety was established by stereoselective reduction, and the cyclopentene structure was secured through a ring-closing metathesis reaction.

DMTMM was used as condensing agent for synthesis of 1,2,4-oxadiazoles from corresponding carboxylic acids and amidoximes in the mixed solvent of THF and NMP. First, carboxylic acids were activated by DMTMM, and then reacted with amidoximes to convert to O-acylated amidoximes. The unusual solvent system THF-NMP successfully promoted dehydration process of O-acylated amidoximes and 1,2,4-oxadiazoles were acquired in one-pot. This methodology provides a convenient and facile synthesis of 1,2,4-oxadiazoles with high yield.

Aerobic oxidative cleavage of alkenes is presented to give aldehydes and ketones under visible light photocatalysis. A series of aryl substituted alkenes were tested to be suitable substrates in this strategy. Evidence proved that the initiation step undergoes an energy transfer pathway, which may help simplify the reaction condition and exhibit high tolerance of the substrate scope.

In contrast to the wide ranging study of EDOT, its derivatives, and polymer PEDOT that followed its commercialisation by the Bayer research laboratory, far fewer investigations have been devoted to the sulfur analog 3,4-ethylenedithiathiophene (EDTT) 13. To the best of our knowledge, there is no reported review highlighting the methodologies available for the synthesis of EDTT and its derived compounds. Hence, this review sumarises the main methods that have been reported for the synthesis EDTT and its chemistry.

A simple and convenient TeflonTM-based method for N-methyltetrapeptide purification relying on fluorous 9-fluorenylmethanol as a C-terminal protecting group was developed. Fluorous compound–protected peptides supported on TeflonTM powder could be easily transferred between the fluorous solid phase (TeflonTM) and the liquid phase (reaction solution) by tuning the hydrophobicity of the solvent. Fluorous peptides present in a homogeneous state in solution during each elongation reaction were immobilized on TeflonTM at the end of each reaction by adjusting the hydrophobicity of the reaction solution, and they could be isolated by simple filtration, affording the facile synthesis of the corresponding N-methylated tetrapeptide.

Aleurodiscal is one of the representative members of the isopropyl trans-hydrindane sesterterpenoid family. Herein, we describe our efforts towards the synthesis of a complex sesterterpenoid, aleurodiscal. The key precursor of the Cope rearrangement was concisely synthesized from a known bicyclic starting material in 13 linear steps. Our approach highlighted a Van Leusen homologation reaction and an oxidative rearrangement of a tertiary carbinol.

We report a rhodium-catalyzed intramolecular [4+3] cycloaddition of 1-sulfonyl-1,2,3-triazoles that enables the efficient synthesis of cyclobutane-fused dihydroazepines in moderate to good yields. Meanwhile, three stereo centers were constructed, and one single diastereomer was obtained in each case. The stereoselectivity control was also discussed.

Presented herein are the first highly diastereoselective, controlled alkylthia-Michael reactions of mercaptans onto α-methylene butanoates. This addition occurs with concomitant lactonization and provides ready access to either the kinetic cis,cis- or thermodynamic cis,trans-butyrolactones under catalytic promotion by tetrabutylammonium hydroxide in methanol.

Abstract not available

This digest aims to comprehensively describe the recent advances in catalytic asymmetric intra- and intermolecular haloamination and haloetherification of olefins. The scopes and strategies of these new methods developed since 2015 will be discussed.

Present study describes a novel, one-pot synthesis of amides of carboxylic acids that involves sequential addition of diphenyl carbonate, an amine catalyst to a carboxylic acid at 60-80 °C to generate a carbonic anhydride (in-situ) that rearranges to a phenyl ester, and is followed by addition of another amine to yield an amide in good to excellent isolated yield. This methodology has successfully been applied to the synthesis of drug molecules (acetaminophen, moclobemide, vorinostat) and intermediates of glipizide, glibenclamide, gedatolisib and enzalutamide drug molecule.

A new approach has been developed for the access of 3-(het)aryl substituted 1H-[1,3]oxazino[3,4-a]indol-1-one derivatives promoted by Pd/Cu-catalysts and ZnCl2. These compounds were prepared via a direct and one-pot method involving the coupling of 2-iodoindole derivatives with a range of terminal alkynes in the presence of (PPh3)4Pd, CuI and ZnCl2 in DMF under ultrasound. This sonochemical approach proceeded via the CC coupling followed by intramolecular cyclization (i.e. CO bond formation) in a regioselective manner in the same pot affording the desired products in good to acceptable yield. The mild reaction conditions, shorter duration and the use of eco-friendly energy are some of the key features of the current methodology. Among the synthesized compounds, the [1,3]oxazino[3,4-a]indol-1-one derivative 3a, 3c and 3f were identified as the preliminary hits when tested in vitro for their TNF-α inhibitory potential.

A thermodynamic-promoting diastereoselective synthesis of dispirooxindole-pyrrolizines was developed by a five-component reaction with a dual 1,3-dipolar cycloadditions process of non-stabilized azomethine ylides that includes the decarboxylation of glycine and αCH functionalization of generated pyrrolidines in situ. This process is a solid and versatile strategy for rapidly assembling fused pyrrolizines with two spirooxindoles bearing seven stereocenters. Homogeneous Brønsted acid catalysis and benign solvent in one-step reaction can be used to promote the green process, with by-products of CO2 and H2O, and potentiating environmental tolerance.

Herein, we report an effective and efficient transition metal-free method wherein benzyne intermediates from silyl aryl triflates were successfully coupled with primary sulfonimidamides. The use of CsF in ACN proved to be the optimal condition for the N-arylation of various substituted primary sulfonimidamides, resulting in good to excellent yields. Further, the addition of 18-crown-6 to the present method extended the scope to tertiary sulfonimidamides, which were obtained in moderate to low yields.

In this study, a formal synthesis of isoquinocyclinone is reported. Synthesis of key intermediate lactone 6, an intermediate in Koert's s total synthesis of isoquinocyclinone, was succeeded. The lactone 6 was synthesized by using our developed diazo-transfer reaction of anthranol with 2-azido-1,3-dimethylimidazolinium chloride (ADMC) and alkoxycarbonylmethylation of diazoquinone as key reactions.

Multiple myeloma (MM) is the biggest normal cancer influencing the bone marrow and remains fatal for maximum patients, hence innovative therapies are taken. Bortezomib is an FDA-permitted drug for the therapy of patients with MM. We emphasized an alternative convergent method is developed for the synthesis of bortezomib molecule. The targeted compound was achieved with excellent yields, improved reaction conditions and mild reagents.