The title compound, C15H18NO3PS·C6H6, is a rare example of a crystallographically characterized exocyclic phosphiniminium-arene-sulfonate zwitterion, which crystallises as its benzene solvate. The crystal structure shows that the N atom is protonated and that the iminium H atom forms both intra- and inter-molecular hydrogen bonds to the single-bonded sulfonate O atom in an R 2 (2)(4) graph-set ...

A short synthetic sequence leading to the formation of the C,D,E-ring subunit of the Aspidosperma alkaloids is reported. This route is based on a ring fragmentation/intramolecular azomethine ylide 1,3-dipolar cycloaddition reaction sequence that gives the desired tricyclic product as a single diastereomer. A γ-amino-β-hydroxy-α-diazo carbonyl compound is shown to fragment in the presence of a L...

A convergent, organocatalytic asymmetric aminomethylation of α,β-unsaturated aldehydes by N-heterocyclic carbene (NHC) and (in situ generated) Brønsted acid cooperative catalysis is disclosed. The catalytically generated conjugated acid from the base plays dual roles in promoting the formation of azolium enolate intermediate, formaldehyde-derived iminium ion (as an electrophilic reactant), and ...

[reaction: see text] A heterogeneous, three-component crotylation of in situ generated N-acyl iminium ions has been developed. This reaction proceeds under ambient temperature in MeCN and is catalyzed by macroporous polystyrene-bound sulfonic acid (MP-TsOH). Workup is accomplished by filtration, upon which the catalyst is recoverable. A range of homoallylic amine equivalents have been prepared ...

Asymmetric N-alkylations of isatins with enals were shown to be feasible via a prolinol-catalyzed iminium activation, and N-alkylated isatins were obtained in good yields and with excellent enantioselectivity. The biologically useful N-alkylated isatins also served as valuable synthetic precursors, and could be readily converted to chiral N-alkylated indole derivatives. The described method pro...

Abstract: 3-(Trifluoromethyl)prop-2-yne 1-iminium triflate salts were generated from 3-trifloxy-3-(trifluoromethyl)prop-2-ene by triethylamine-assisted elimination of triflic acid and trapped in situ various cycloaddition reactions. These included Diels-Alder reactions with 1,3-dienes, [2+2] 1,4-diphenylbuta-1,3-diene, [3+2] organoazides. All these revealed the excellent dienophilic dipolarophi...

Abstract A new easy‐to‐synthesize solid supported Eosin Y and its application in the building of a catalytic continuous flow reactor is reported. The fluidic device was employed to perform tertiary amines in‐flow photooxidations followed by nucleophile addition, with overall productivity increased one order magnitude. When using iminium‐ions situ generated or telescoped fashion, resulting Manni...