BACKGROUND Derivatives of D-glucosamine and D-galactosamine represent an important family of the cell surface glycan components and their fluorinated analogs found use as metabolic inhibitors of complex glycan biosynthesis, or as probes for the study of protein-carbohydrate interactions. This work is focused on the synthesis of acetylated 3-deoxy-3-fluoro, 4-deoxy-4-fluoro and 3,4-dideoxy-3,4-d...

Difluoromethanesulfonyl hypervalent iodonium ylides 2 were developed as electrophilic difluoromethylthiolation reagents for a wide range of nucleophiles. Enamines, indoles, β-keto esters, silyl enol ethers and pyrroles were effectively reacted with 2 affording desired difluoromethylthio (SCF2H)-substituted compounds in good to high yields under copper catalysis. The reaction of allyl alcohols w...

1,6-Enynes bearing OR groups at the propargyl position generate α,β-unsaturated gold(I)-carbenes/ gold(I) stabilized allyl cations that can be trapped by alkenes to form cyclopropanes or 1,3-diketones to give products of α-alkylation. The best migrating group is p-nitrophenyl ether, which leads to the corresponding products without racemization. Thus, an improved formal synthesis of (+)-schisan...

Visible-light photoredox catalysis has been utilized in a new multicomponent reaction forming β-functionalized δ-diketones under mild conditions in an operationally convenient manner. Single-electron reduction of in situ generated carboxylic acid derivatives forms acyl radicals that react further via 1,2-acylalkylation of olefins in an intermolecular, three-components cascade reaction, giving v...

New series of 2,3-disubstituted quinazolin-4(3H)one were synthesized via the reaction of the readily obtainable 2-thioxo-3-phenyl-quinazolin-4(3H)one 1 with ethyl chloroacetate followed by hydrazinolysis to afford the hydrazide 3 which allowed to react with different electrophilic reagents such as carbon disulphide, phenyl isothiocyanate, β-diketones, anhydrides, acrylonitrile, ethyl cinnamate,...

In photoinduced molecular reaction dynamics, the effects of electronic charge redistribution can lead to multiple pathways that are determined by the nature of the initial structures involved and the environment the molecule of interest is studied in. The β-diketones are a common example of this complexity. They show keto-enol tautomerism that is almost totally shifted toward the enolic form. H...

An eight-step linear sequence for the preparation of two diastereomers an 8-fluoro-ABC-steroid building block was developed. Key step intramolecular Diels–Alder reaction intermediate o-quinodimethane formed from a benzocyclobutene substituted with 5-fluorohex-5-en-4-one chain. This side chain prepared 6-chlorohex-1-ene by bromofluorination, elimination HBr, Finkelstein and alkylation literature...