Synthesis and Structure of [Fc(EtO)PS2]‐ Complexes

Reaction of Fc(S)PS₂P(S)Fc with NaOEt gives the non symmetric phosphonodithioato anion [Fc(EtO)PS₂]^‐ which can be complexed to a range of metal ions. The group 10 metals (Ni, Pd and Pt) adopt [ML₂] complexes with square planar coordination. The first known mercury phosphonodithioate complex is shown to adopt a unique dimeric [M₂L₄] structure. A new structural motif for lead phosphonodithioate complexes is reported consisting of [PbL₂] units joined by Pb···S interactions to form distinct dimeric pairs. All new compounds have been characterized spectroscopically and four demonstrative X‐ray structures are reported.     

The preparation and characterisation of bimetallic iridium(II) complexes containing derivatised bridging naphthalene-1,8-disulfur or 4,5-dithiolato acephenanthrylene ligands

Oxidative addition of the disulfide compounds naphtho[1,8-cd][1,2]dithiole, 2-tert-butylnaptho[1,8-cd][1,2]dithiole, 2,7-di-tert-butylnaphtho[1,8-cd][1,2]dithiole, 4,5-dithiaacephenanthrylene and the thio/sulfinyl and thio/sulfonyl compounds naphtho[1,8-cd][1,2]dithiole 1-oxide, and naphtho[1,8-cd][1,2]dithiole 1,1-dioxide respectively to [[Ir(mu-Cl)(cod)](2)] give dinuclear Ir-Ir bonded Ir(II) compounds [[IrCl(cod)](2)(mu(2)-1,8-S(2)-nap)] 1, [[IrCl(cod)](2)(mu(2)-1,8-S(2)-2-(t)Bu-nap)] 2, [[IrCl(cod)](2)(mu(2)-1,8-S(2)-2,7-di-(t)Bu-nap)]] 3, [[IrCl(cod)](2)(mu(2)-4,5-S(2)-phenan)] 4, [[IrCl(cod)](2)(mu(2)-1-S,8-[S(O)]-nap)] 5 and [[IrCl(cod)](2)(mu(2)-1-S,8-[S(O)(2)]-nap)] 6 where the di-sulfur ligands act as bridges between the two Ir(II) metal centres. The compounds were obtained in moderate to good yields as orange or deep red powders or crystalline solids. Five of the new complexes have been structurally characterised and were found to have Ir-Ir bond lengths in the range 2.7630(8) to 2.8113(11) A.     

alpha,beta,gamma-Trifluoroalkanes: a stereoselective synthesis placing three vicinal fluorines along a hydrocarbon chain

A regio- and stereoselective method for the synthesis of alpha,beta,gamma-trifluoroalkanes is described which allows the synthesis of single diastereoisomers of this structural motif. The methodology relied upon regiospecific and stereospecific hydrogen fluoride ring opening of allylic epoxides and then Sharpless cyclic sulfate methodology followed by nucleophilic fluoride attack to introduce the second fluorine. The resultant difluoro alcohol was converted to its triflate which was also displaced by fluoride ion to generate the alpha,beta,gamma-trifluoroalkanes.     

A new synthesis of (PhPSe2)2 (Woollins reagent) and its use in the synthesis of novel P-Se heterocycles

A new and improved method for the preparation of (PhPSe2)2 (Woollins reagent (WR), 1) is reported. Reaction of dichlorophenylphosphine with Na2Se, (prepared from the reaction of elemental selenium and sodium in liquid ammonia) gives WR with excellent purity, high yield and on a larger scale than was previously possible. Four novel phosphorus-selenium heterocycles, including a spirocyclic heterocycle exhibiting a four-membered P2SeC ring, were obtained from the reaction of WR with two reactive substrates (diphenylcyclopropenone and methyl phenylpropiolate). Useful selenocarbonyl and thiocarbonyl compounds were obtained from the reaction of both WR and Lawesson's reagent with diphenylcyclopropenone. All new compounds were characterised spectroscopically and three demonstrative X-ray structures are reported.     

Dirhodium(II) tetraacetate catalysed reactions of diazo thioamides: isolation and cycloaddition of anhydro-4-hydroxy-1,3-thiazolium hydroxides (thioisomünchnones), an approach to analogues of dehydrogliotoxin

Dirhodium(II) tetraacetate catalysed reaction of the indoline diazo thioamide 8 gives the thioisomünchnone 9, a stable characterisable solid. This masked thiocarbonyl ylide undergoes 1,3-dipolar cycloaddition with N-methylmaleimide and maleic anhydride to give the exo-cycloadducts 10 and 11, characterised by X-ray crystallography. The thioisomünchnone 18, derived from diazo thioamide 17, is an extremely stable crystalline mesoionic system which can be characterised by X-ray crystallography but fails to undergo intramolecular cycloaddition. The related thioisomünchnone 19 can be generated by reaction of indoline-2-thione 7 with bromoacetyl chloride in the presence of triethylamine, and undergoes cycloaddition to give adducts 20 and 21.     

New Functionalised Phosphorus (III) Ligands

Abstract

Whereas the number of functionalised tertiary phosphines, and to a lesser extent phosphites, has flourished in recent years, related systems bearing one (or more) P-N bonds are poorly developed. Here we describe a facile synthetic route to some new, potentially hemilabile, P,O-hybrids. These ligands are of particular interest for use in catalysis[1] and also as suitable precursors for further functionalisation.