A DAST-free route to aryl(difluoromethyl)phosphonic esters

Nitrenium Ion Azaspirocyclization−Spirodienone Cleavage: A New Synthetic Strategy for the Stereocontrolled Preparation of Highly Substituted Lactams and N-Hydroxy Lactams

“…Although the 1,2-reduction of 2,5-cyclohexadienones is well documented, a potential caveat with this plan was the propensity of the reduction products 31 to potentially undergo rearrangement during purification . Fortunately, reduction of dienone 12c , under Luche conditions (NaBH 4 , CeCl 3 , MeOH), proceeded rapidly at 0 °C to give a mixture of diastereomers 31 , which could be isolated with excellent mass recovery.…”

Electrolytic Partial Fluorination of Organic Compounds. 23.1 Regioselective Anodic Difluorination of Sulfides Using Novel Fluorine Source Et4NF·4HF

“…It is remarkable that anodic difluorination proceeded with such a high regioselectivity despite higher anodic potential required for difluorination compared to monofluorination. Phosphonate derivative 1c was also difluorinated in fairly good yield, and the difluorinated product 3c should be a promising building block for biologically interested difluoromethylenephosphonates 20 (run 3). The yield of difluorinated product from cyano derivative 1d was rather low (run 4).…”

Nucleophilic Difluoromethylenation of Ketones Using Diethyl (Difluoro(trimethylsilyl)methyl)phosphonate Mediated by 18-Crown-6 Ether/KOAc

“…In this context, a straightforward method is the addition of (diethylphosphinyl)­difluoromethyl carbanion to carbonyl compounds. A common method is the use of strong bases such as LDA to deprotonate diethyl (difluoromethyl)­phosphonate to react with aldehydes or ketones, , which are usually carried out at low reaction temperature. To make the reaction conditions milder, the use of diethyl (difluoro­(trimethylsilyl)­methyl)­phosphonate 5 as a carbanion equivalent becomes popular .…”