Three-Component Reaction of Triphenylphosphine, Acetylenic Esters, and 6-Aminouracil or 6-Amino-N,N′-dimethyluracil

One-pot multi-component synthesis of diverse bioactive heterocyclic scaffolds involving 6-aminouracil or its N-methyl derivatives as a versatile reagent

The present review summarizes all the multi-component reaction strategies reported during last two decades for the synthesis of diverse bioactive heterocyclic scaffolds involving 6-aminouracil or its N-methyl derivatives.

Glycoconjugates via phosphorus ylides

A facile, high yielding access to rare chimeric compounds combining phosphorus ylides with complex glycosyl formamides is described. We determined x-ray structures gaining structural insight into this compounds class. In addition, data mining of similar compounds deposited within the Cambridge Structural Database was performed. These derivatives could be used either as synthetic intermediates via the ylide functionalization and glyco chemical biology synthons or improving the pharmacokinetic properties of a potential bioactive molecule, exploiting the glycosyl moiety.

Vinylphosphonium and 2-aminovinylphosphonium salts - preparation and applications in organic synthesis

The main synthetic routes towards vinylphosphonium salts and their wide applications in organic synthesis are discussed in this review. Particular attention is paid to the use of these compounds as building blocks for the synthesis of carbo- and heterocyclic systems after their prior transformation into the corresponding phosphorus ylides, followed by the intramolecular Wittig reaction with various types of nucleophiles containing a carbonyl function in their structures.

A reinvestigation of mono- and bis-ethynyl phosphonium salts: structural and computational studies and new reactivity

A series of mono- and bis-ethynyl phosphonium salts have been prepared via reaction of bromoacetylenes, Ph–C≡C–Br or Br–C≡C–C6H4–C≡C–Br, with various phosphines. Some of the derivatives reported are previously known, ([Ph–C≡C–PPh3]Br, [Ph–C≡C–PMe3]Br, [Ph–C≡C–PBu3]Br, and [Ph3P–C≡C–C6H4–C≡C–PPh3][Br2]), however typically these are missing complete spectroscopic characterization and many have been prepared using much more complicated methods. The derivative [Ph–C≡C–PPh3]Br is capable of inhibiting the growth of tumour cells and has been shown crystallographically to have a significant interaction with the heat shock proteins (HSP70 or DnaK). Thus, solid state structures for all seven phosphonium salts prepared have been reported as they may be of interest to others in this field. Sterically encumbered phosphines such as Mes3P did not react with Ph–C≡C–Br; however, (2,4,6-MeO–C6H2)3P was found to slowly react at moderate temperature to give the expected alkynyl phosphonium salt. However, at higher temperatures, the alkynyl phosphonium undergoes an intramolecular cyclization to form a phosphonium analogue of a 1,4-oxazine. Finally, electronic structure calculations reveal the positive charge on the acetylenic β-carbon, a result of a significant contribution of other canonical structures. The flexibility of the P–C≡C bond has been investigated showing a low-energy barrier (<5 kcal/mol) for bending up to 40° from the optimized angle in the model [Ph–C≡C–PMe3]+ cation. This ease of bending may be of significance in the development of other alkynyl phosphonium tumour cell growth inhibitors.

Synthesis of heterocyclic scaffolds through 6-aminouracil-involved multicomponent reactions

There is a wide range of multicomponent reactions that include 6-aminouracil in the synthesis of heterocyclic compounds. This review highlights the advances in the use of 6-aminouracil in the synthesis of various organic compounds.

Theophylline as the catalyst for the diastereoselective synthesis of trans-1,2-dihydrobenzo[a]furo[2,3-c]phenazines in water

Theophylline-catalyzed efficient and environmentally benign procedure for the diastereoselective synthesis of trans-1,2-dihydrobenzo[a]furo[2,3-c]phenazines with pyridinium ylide assisted domino reaction in water.