C‐Glycosides are valuable organic compounds in the field of medicinal chemistry due to their ubiquity inside living systems and pronounced biological activity. Herein, we describe an approach to ...alkyl‐ketones bearing glycal units via the Pd‐catalyzed carbonylative coupling of 2‐iodoglycals and alkyl and aryl halides. Examples bearing a variety of functional groups are presented as well as a mechanistic proposal for this transformation.
A versatile C(sp2)–C(sp3) carbonylative Negishi‐type reaction allowing the access to glyco‐ketones bearing alkyl and aryl groups is described in this report. The tolerance for different functional groups as well as protecting groups denote the usefulness of the methodology.
The synthesis of C‐glycosides is of great importance in the field of carbohydrate chemistry given its ubiquity in biologically active molecules. Herein, we describe a protocol for the Pd‐catalyzed ...carbonylative Heck reaction of activated olefins and 2‐iodoglycals. A variety of α,β‐unsaturated 2‐ketoglycosides were obtained in up to 89 % yield using d‐glucal, d‐galactal, d‐xylal, and l‐arabinal derivatives.
The synthesis of biologically relevant C‐ketoglycosides, found in many important natural products and medicinally active molecules is reported. This strategy allows to connect a series of glycal units to activated olefins via the Pd‐catalyzed carbonylative Heck cross‐coupling reaction.
The carbonylative cross‐coupling reactions of 2‐iodoglycals with thiols and selenols in the presence of molybdenum hexacarbonyl as a solid source of carbon monoxide is described. This methodology ...permitted the synthesis of 29 C2‐glycosides bearing thioester and selenoester functionalities in moderate to excellent yields and high functional group tolerance. Moreover, this communication describes the first catalytic carbonylative coupling reaction of selenols with a carbon electrophile.
Are you in a rush? Carbonylative cross‐coupling reactions of 2‐iodoglycals with thiols (RSH) and selenols (RSeH) in the presence of molybdenum hexacarbonyl as a solid source of carbon monoxide is described. A useful methodology for the synthesis of chalcogen‐containing C2‐glycosides with high functional group tolerance.
The synthesis of amidoglucals and glucal esters in good to high yields using 2-iodo-3,4,6-tri-
O
-acetyl-
d
-glucal as a substrate, Mo(CO)
6
as a carbon monoxide source and PdCl
2
as a catalyst is ...reported. This procedure shows advantages when compared to other published methodologies, as it is carried out in one pot relying on short reaction times at mild temperatures, under ligand-free conditions and with only one equivalent of Mo(CO)
6
.
The iron(III)‐promoted synthesis of densely‐substituted 4H‐chalcogenchromene from organochalcogen propargylamines in the presence of diaryl dichalcogenides is reported. Subsequent ...C2‐functionalization with electrophiles and potassium trifluoroborate salts via Suzuki‐Miyaura coupling reaction are also presented. A plausible mechanism based on HRMS experiments is proposed and discussed.
Herein we report a novel Mo-catalyzed carbonylative Sonogashira cross-coupling between 2-iodoglycals and terminal alkynes. The reaction displays major improvements compared to a related Pd-catalyzed ...procedure previously published by our group, such as utilizing unprotected sugar derivatives as starting materials and tolerance to substrates bearing chelating groups. In this work we also demonstrate the utility of the glyco-alkynone products as platform for further functionalization by synthesizing glyco-flavones
Au-catalyzed 6-
-dig cyclization.
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•Novel multi-component syntheses of pyrimidines developed for the first time using β-CD in aqueous medium.•The β-cyclodextrin is recyclable, inexpensive, economically-viable, ...non-toxic, and readily available.•Multi-component reactions (MCRs), green synthesis, and short reaction times for the synthesis of pyrimidines.
Using β-cyclodextrin (β-CD) as a catalyst pyrimidine derivatives were synthesized for the first time in aqueous medium. β-CD is a recyclable, inexpensive, economically viable, non-toxic, and readily available material. Various aldehydes were used with ammonium acetate, and 1,3-diketones to generate a series of pyrimidine derivatives in good to excellent yields.
A series of oxazoline based compounds was obtained via amidation formation from salicylic acid derivatives and benzyl-protected l-threonine with good yields (50–90%). These compounds present ...absorption in the UV region (∼300 nm) and fluorescence emission spectra show large Stokes shift emission (∼10000 cm−1) in the blue-green region attributed to the ESIPT process. TD-DFT calculations were carried out to investigate the process of proton transfer of the structure of both tautomers (keto and enol) and corroborating the UV region absorption and large Stokes shift. The oxazolines derivatives were investigated as optical sensor for enantiomeric identification in solution. Preliminary results indicate sensing for arabinose and tartaric acid, but not specificity. However, to the pair R-(−)-Mandelic and S-(+)-Mandelic acid, the oxazoline 4c showed a enantiomeric selectivity identification, allowing to envisage these compounds as potential photoactive building blocks to propose innovative optical sensors in solution.
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•A series of oxazoline derivatives able to proton transfer in the excited state were synthesized.•Compounds exhibited absorption maxima in the UV region.•Emission with large Stokes shift (∼10000 cm−1) in the blue-green region.•Optical sensor for enantiomeric identification in solution.
Because of the increased resistance to currently available antifungals, fungal infections represent a significant challenge to human health. Herein, we report the synthesis of 2-aryloxazoline ...derivatives from the reaction between l-threonine and derivatives of salicylic or naphthoic acid. In total, 26 compounds were obtained and tested against species of Candida, Cryptococcus, and Aspergillus. We found that all of the compounds inhibited the growth of Candida species at low concentrations (<0.25 μg/mL) and exhibited reduced hemolytic and cytotoxic activities. Additionally, compounds 4i and 9i were especially effective against antifungal-resistant isolates and the emerging fungus Candida auris. However, the compounds were less active on Cryptococcus and Aspergillus. Because of the improved in vitro antifungal efficacy and attenuated cytotoxicity, these two 2-aryloxazolines obtained from salicylic and naphthoic acid derivatives, respectively, may be considered lead molecules for the development of novel antifungal drugs.
A carbonylative Sonogashira coupling approach to the synthesis of glyco-alkynones is described. Eighteen examples were obtained in moderate do nearly quantitative yields under mild conditions ...employing Mo(CO)
as a safe carbon monoxide source. Functionalization of the alkynyl moiety
cycloaddition with organic azides provided six examples of glyco-triazoles.
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