Highly selective difluoromethylations of β-keto amides with TMSCF2Br under mild conditions

Without employing any transition metal and other additives, efficient methods for selective difluoromethylations of β-keto amides with TMSCF2Br reagent have been developed under mild conditions. This protocol allows a convenient access to various α-difluoromethyl β-keto amides with excellent yields (up to 93%) and high C/O regioselectivities (up to 99:1). The C/O selectivity of β-keto amides could be easily reversed and controlled by simply changing the base. This protocol can be easily scaled up and the C-difluoromethylation product could be reduced into CF2H contained amino-alcohol derivatives. Moreover, the first enantioselective electrophilic difluoromethylation of β-keto amides has been achieved by phase-transfer catalysis.

Highly selective difluoromethylations of β-keto amides with TMSCF2Br under mild conditions

Without employing any transition metal and other additives, efficient methods for selective difluoromethylations of β-keto amides with TMSCF2Br reagent have been developed under alkaline and open-air conditions. This protocol allows a convenient access to various α-difluoromethyl β-keto amides with excellent yields (up to 93%) and high C/O regioselectivities (up to 99:1). The C/O selectivity of β-keto amides could be easily reversed and controlled by simply changing the base. This protocol can be easily scaled up and the C-difluoromethylation product could be reduced into amino-alcohol derivatives. Moreover, the first enantioselective electrophilic difluoromethylation of β-keto amides has been achieved by phase-transfer catalysis.

Silver-Catalyzed Decarboxylative Radical Relay Difluoroalkylation-Carbocyclization: Convenient Access to CF2-Containing Quinolinones

We report a practical Ag-catalyzed decarboxylative difluoroalkylation–carbocyclization reaction. Various structurally diverse gem-fluorinated quinolinones were obtained in moderate to good yields. Mechanistic studies suggested that the catalytic system involved a formal...

Catalytic Enantioselective Synthesis of Chiral Spirocyclic 1,3-Diketones via Organo-Cation Catalysis

An SPA-triazolium bromide catalyzed transannular C-acylation of enol lactones is presented. This methodology provides convenient access to a range of enantioenriched spirocyclic 1,3-diketones in moderate to high yields and enantioselectivities...

Modular Synthesis of 3-Substituted Isocoumarins via Silver-Catalyzed Aerobic Oxidation/6-Endo Heterocyclization of ortho-Alkynylbenzaldehydes

A method involving silver-catalyzed aerobic oxidation/6-endo heterocyclization of ortho-alkynylbenzaldehydes to yield 3-substituted isocumarins is described. The developed protocol allows convenient access to a range of synthetically useful 3-substituted isocoumarins and...

The “Country of cities” web-GIS: development experience and approaches used in creating a history-oriented geoportal

Providing convenient access to spatial information for multiple users is a big challenge. To solve this problem, researchers present the results of their research on thematic geoportals—geographic information systems (GIS) located on the Web. The main functionality of such web-GIS, in addition to directly displaying interactive spatial information, is the possibility of making custom searches, measuring lengths and areas, and providing access to related multimedia materials. Archaeological geoportals, unlike other thematic GIS, require special approaches to the implementation, as there is a necessity to provide convenient access not only to spatial information, but also a gallery of multimedia materials, as well as detailed descriptions. This paper describes the approach to the development of cartographic web-resource “Country of Cities” which provides access to the results of interdisciplinary research of Volga Bulgarian settlements. for user-friendly access to both cartographic and descriptive materials, it was decided to divide the geoinformation and analytical component into two separate but interconnected portals within one web resource. Web-GIS is based on the leaflet library and provides interactive access, besides the information about each ancient settlement itself, to the series of analytical maps—risk map of the development of exogenous processes, risk map of the destruction of ancient settlements, their present state, and many others. The main graphic and descriptive materials are presented on the web portal, where a special page was created for each ancient settlement with a descriptive block, a gallery with images of the settlement from an unmanned aerial vehicle, thematic and historical maps, as well as an interactive three-dimensional textured model of the corresponding archaeological site.

Highly diastereoselective synthesis of vicinal diamines via Rh-catalyzed three-component reaction of diazo compounds with diarylmethanimines and ketimines

A Rh-catalyzed diastereoselective three-component reaction of diazo compounds with diarylmethanimines and ketimines has been reported, which offers an efficient and convenient access to furnish vicinal diamine derivatives with two tertiary...

A convenient access to fluorophosphonium triflate salts by electrophilic fluorination and anion exchange

The in situ one-pot electrophilic fluorination of phosphanes with NFSI followed by anion exchange with MeOTf gives highly electrophilic fluorophosphonium triflates – highly efficient catalysts for the synthesis of N-sulfonylamidines from amides.