Tommy Johansson

Palladium-Catalyzed Propargylic Substitution with Phosphorus Nucleophiles: Efficient, Stereoselective Synthesis of Allenylphosphonates and Related Compounds

A new, efficient method is developed, based on a palladium(0)-catalyzed reaction of propargylic derivatives with various phosphorus nucleophiles, to produce allenylphosphonates and their analogues with defined stereochemistry in the allenic and the phosphonate moiety.

Studies Towards Synthesis of Dinucleoside Arylphosphonates with Metal Complexing Properties

Abstract An efficient and stereospecific synthesis of dinucleoside 4′-(2,2′:6′,2″-terpyridyl)phosphonate 2 and 5-(2,2′-bipyridyl)phosphonate 3 via a palladium(0) cross coupling strategy has been developed.

2-Pyridylphosphonates: a new type of modification for nucleotide analogues

Suitably protected dithymidine H-phosphonates afforded the corresponding dinucleoside 2-pyridylphosphonates upon treatment with N-methoxypyridinium tosylate in acetonitrile in the presence of 1,8-diazabicylo[5.4.0]undec-7-ene (DBU). The reaction was rapid (ca. 5 min), practically quantitative and proceeded stereospecifically, most likely with retention of configuration at the phosphorus centre.

The case for configurational stability of H-phosphonate diesters in the presence of diazabicyclo[5.4.0]undec-7-ene (DBU).

Configurational stability of dinucleoside H-phosphonates and the stereochemical course of their sulfurisation in the presence of diazabicyclo[5.4.0]undec-7-ene (DBU) were investigated using 31P NMR spectroscopy. It was found that under the reaction conditions and irrespective of the type of protecting groups present in the nucleoside moieties, the H-phosphonate diesters investigated did not undergo any detectable epimerisation at the phosphorus centre, and their sulfurisation with elemental sulfur in the presence of DBU, proceeded stereospecifically. Thus, we could not confirm reports from another laboratory on a stereoselective course of sulfurisation of H-phosphonate diesters and the corresponding acylphosphonates in the presence of DBU.

Developing Synthetic Methods for Bioactive Phosphorus Compounds Using H-Phosphonate Chemistry: A Progress Report

Abstract In this paper a short account of our recent research concerning the development of new synthetic methods and reagents for the preparation of nucleotides and their analogues, is given.

The Influences of A Nitrogen Atom Position in Dinucleoside 2-,3-,4-Pyridylphosphonates on Fragmentation Patterns in Electrospray Ionization Multistage Tandem Mass Spectra

2-,3-,4-Pyridylphosphonates and their phosphonothioate congeners were analyzed by electrospray ionization multistage tandem mass spectrometry (ESI-MSn). It was found that the fragmentation pathways of these compounds were not influenced to any detectable extent by the stereochemistry at the phosphorus centers but were sensitive to the position of a nitrogen atom in the pyridine ring of these compounds. Possible mechanisms for fragmentations of the investigated compounds are discussed in detail. In honor and celebration of the life and career of John A. Montgomery.

Synthesis of Nucleotide Analogues with Pyridylphosphonate and Pyridylphosphono thio ate Internucleotide Linkages

Efficient synthetic methods for the preparation of dinucleoside 4-pyridyl-, 3-pyridyl-, and 2-pyridylphosphonates have been developed.