Iodine-catalyzed C3-formylation of indoles using hexamethylenetetramine and air

TBHP/Et3N-Promoted Chemoselective Formylation and Peroxidation of Pyrrolo[2,1-a]isoquinolines

An efficient formylation of pyrrolo[2,1-a]isoquinoline derivatives has been reached by the use of TBHP (tBuOOH) and Et3N as the mediator. In this strategy, CHO and CDO can be readily incorporated into heteroarenes by the utilization of CHCl3 and CDCl3 as the carbonyl sources. Interestingly, a solvent-controlled chemoselectivity was observed. The use of PhCl as a solvent resulted in dearomatization and peroxidation of pyrrolo[2,1-a]isoquinolines, delivering functionalized peroxides in 53-64% yields.

Studies of Cytotoxicity Effects, SARS-CoV-2 Main Protease Inhibition, and in Silico Interactions of Synthetic Chalcones

SARS-CoV-2 main protease (M^pro ) plays an essential role in proteolysis cleavage that promotes coronavirus replication. Thus, attenuating the activity of this enzyme represents a strategy to develop antiviral agents. We report inhibitory effects against M^pro of 40 synthetic chalcones, and cytotoxicity activities, hemolysis, and in silico interactions of active compounds. Seven of them bearing a (E)-3-(furan-2-yl)-1-arylprop-2-en-1-one skeleton (10, 28, and 35-39) showed enzyme inhibition with IC₅₀ ranging from 13.76 and 36.13 μM. Except for 35 and 36, other active compounds were not cytotoxic up to 150 μM against THP-1 and Vero cell lines. Compounds 10, and 35-39 showed no hemolysis while 28 was weakly hemotoxic at 150 μM. Moreover, molecular docking showed interactions between compound 10 and M^pro (PDBID 5RG2 and 5RG3) with proximity to cys145 and His41, suggesting a covalent binding. Products of the reaction between chalcones and cyclohexanethiol indicated that this binding could be a Michael addition type.

Formylation and Bromination of Pyrrolo[2,1-a]isoquinoline Derivatives with Bromoisobutyrate and Dimethyl Sulfoxide

We have developed an efficient formylation of pyrroloisoquinolines using bromoisobutyrate and dimethyl sulfoxide as carbonyl reagent. Various formylated pyrroloisoquinolines could be prepared in good yields (up to 94%). This formylation process can be easily scaled up to gram scale with good yield. In most cases of pyrroloisoquinolines without methoxy groups, the combination of bromoisobutyrate and dimethyl sulfoxide could act as a bromination reagent, delivering brominated pyrroloisoquinolines in acceptable to good yields (up to 82%).

Molecular iodine mediated oxidative cleavage of the C–N bond of aryl and heteroaryl (dimethylamino)methyl groups into aldehydes

An efficient iodine mediated conversion of aryl or heteroaryl (dimethylamino)methyl compunds to aryl or heteroaryl aldehydes is achieved via cleavage of C-N bond.

Revisiting applications of molecular iodine in organic synthesis

Molecular iodine contributes significantly to organic transformations in synthetic organic chemistry. It works effectively due to its mild Lewis acidic character, ability as an oxidizing agent, good moisture stability, and easy availability.

Electrochemically Enabled C3-Formylation and -Acylation of Indoles with Aldehydes

Reported herein is an effective strategy for oxidative cross-coupling of indoles with various aldehydes. The strategy is based on a two-step transformation via a well-known Mannich-type reaction and a C-N bond cleavage for carbonyl introduction. The key step-the C-N bond cleavage of the Mannich product-was enabled by electrochemistry. This strategy (with over 40 examples) ensures excellent functional-group tolerance as well as late-stage functionalization of pharmaceutical molecules.

A copper(ii)-catalyzed annulative formylation of o-alkynylanilines with DMF: a single-step strategy for 3-formyl indoles

In this paper, a copper(ii)-catalyzed reaction of o-alkynylanilines with dimethylformamide (DMF) in the presence of oxygen has been developed for synthesizing multisubstituted 3-formyl indole scaffolds.