Palladium(ii) complexes bearing mesoionic carbene ligands: catalytic application in domino Sonogashira coupling/cyclization reactions for one-pot synthesis of benzofuran and indole derivatives.

Bioactive heterocycles such as benzofuran and indole derivatives were synthesized from commercially available 2-iodoarenes and alkynes domino Sonogashira coupling followed by cyclization reaction using well-defined palladium PEPPSI (Pyridine Enhanced Precatalyst Preparation Stabilization and Initiation) complexes (2a and 2b). These reactions tolerate a variety of 2-iodoarenes and diversely substituted terminal alkynes, resulting in the corresponding product in moderate to good yields in an open-air atmosphere. In particular, two palladium(ii) PEPPSI complexes 2a and 2b were synthesized in good yields from the reaction of corresponding 1,2,3-triazol-5-ylidene (MIC: mesoionic carbene), PdCl, KI, and KCO in pyridine at 110 °C and structurally characterized by various spectroscopic techniques including NMR spectroscopy, IR spectroscopy, HRMS and elemental analysis studies.

Temperature-Assisted Generation of Arylmethyl Radicals from Bis(arylmethyl)tin Dichlorides: Efficient Reagents for - Bond-Forming Reactions.

The oxidative-addition reaction between an arylmethyl chloride (RCH Cl; R=1-C H , 2,4,6-Me C H , 4-MeC H , 3-MeC H , C H , 4-ClC H ) and tin powder in boiling toluene produces bis(arylmethyl)tin dichlorides, [(RCH ) SnCl ] in good yields. At 160 °C in mesitylene bis(1-naphthylmethyl)tin dichloride undergoes Sn-C homolytic cleavage to generate two 1-naphthylmethyl radicals (1-C H CH ⋅) which were trapped by TEMPO (C H NO⋅). Subsequently, the radicals (RCH ⋅) produced in this manner were utilized for efficient substitution reactions with electron-rich arenes (R'H; R'=2,4,6-Me C H , 1,2,4,5-Me C H, 1,2,3,4,5-Me C ) to obtain a variety of unsymmetrical diarylmethanes (RR'CH ).

1-Hy-droxy-4-methyl-pyridinium chloride.

The title salt, CHNO·Cl, contains two cations and two anions in the asymmetric unit. The components are linked by O-H⋯Cl and C-H⋯Cl hydrogen bonds, leading to tetra- (square-planar) or penta-coordinated (square-pyramidal) chloride ions. The title salt is isostructural with its bromide analogue.

s-Block metal complexes of PC(H)P-bridged chalcogen-centred methanides: comparisons with isoelectronic PNP-bridged monoanions.

The chemistry of the chalcogen-centred methanides [HC(PR2E)2]- (E = S, Se, Te; R = alkyl, aryl) (PC(H)P-bridged anions) is less well-developed than that of the isoelectronic imidodiphosphinates [N(PR2E)2]-, which are PNP-bridged analogues. The objective of this Perspective is to compare the chemistry of s-block metal complexes of the PC(H)P- and PNP-bridged anions in the context of synthetic approaches, X-ray (solid-state) structures, multinuclear NMR spectra, redox behaviour, and applications in coordination and inorganic heterocyclic chemistry. The related monochalcogeno-centred anions [HC(PR2)(PR2E)]- and [N(PR2)(PR2E)]- (E = S, Se, Te; R = alkyl, aryl) are also included in the discussion.

Synthesis of a labile sulfur-centred ligand, [S(H)C(PPh2S)2](-): structural diversity in lithium(i), zinc(ii) and nickel(ii) complexes.

A high-yield synthesis of [Li{S(H)C(PPh2S)2}]2 [Li2·(3)2] was developed and this reagent was used in metathesis with ZnCl2 and NiCl2 to produce homoleptic complexes 4 and 5b in 85 and 93% yields, respectively. The solid-state structure of the octahedral complex [Zn{S(H)C(PPh2S)2}2] (4) reveals notable inequivalence between the Zn-S(C) and Zn-S(P) contacts (2.274(1) Å vs.

Spirocyclic, macrocyclic and ladder complexes of coinage metals and mercury with dichalcogeno P2N2-supported anions.

Metathetical reactions of alkali-metal derivatives of the dianion [(t)BuN(Se)P(μ-N(t)Bu)2P(Se)N(t)Bu](2-) ((2Se2-)) with Ag(NHC)Cl, Ag[BF4], AuCl(THT) and HgCl2, as well as the reaction of 2S(2-) with AuCl(THT) were investigated. The observed products all incorporate the monoprotonated ligands 2SeH(-) or 2SH(-) in a variety of structural arrangements around the metal centres, including tetrameric and trimeric macrocycles [Ag and Au (E = Se)], a ladder (Au, E = S) and a spirocycle (Hg); the ladder contains both the dianion 2S(2-) and the monoanion 2SH(-) as ligands linking three Au2 units. All complexes have been characterised in the solid state by single crystal X-ray analyses and in solution by multinuclear ((1)H, (31)P and (77)Se) NMR spectra.

1,1'-(Diselanediylbis{[P,P-diphenyl-N-(tri-methyl-sil-yl)phospho-rimido-yl]methanylyl-idene})bis-[1,1-diphenyl-N-(tri-methyl-sil-yl)-λ(5)-phosphanamine] pentane disolvate.

The title compound, C62H78N4P4Se2Si4·2C5H12, is made up of two [SeC(PPh2NSiMe3)(PPh2NHSiMe3)] units related by an inversion center situated at the mid-point of the diselenide bond. It crystallized with two disordered mol-ecules of pentane used as solvent of crystallization. It is a rare example of an anti-periplanar diselenide and exhibits a long Se-Se bond of 2.

A planar dianionic ditelluride and a cyclic tritelluride supported by P2N2 rings.

Oxidation of alkali metal derivatives of [Te((t)BuN)P(μ-N(t)Bu)(2)P(N(t)Bu)Te](2-) with I(2) produces the intermediate ditelluride dianion [Te((t)BuN)P(μ-N(t)Bu)(2)P(N(t)Bu)Te](2)(2-) with a planar PTeTeP conformation and, subsequently, the cyclic tritelluride [((t)BuN)P(μ-N(t)Bu)(2)P(N(t)Bu)(μ-TeTeTe)].

Planar P(6)E(6) (E = Se, S) macrocycles incorporating P(2)N(2) scaffolds.

Oxidation of alkali metal derivatives of the dianions [E((t)BuN)P(μ-N(t)Bu)(2)P(N(t)Bu)E](2-) (E = S, Se) with I(2) produces 15-membered macrocycles in which a planar P(6)E(6) motif is stabilised by perpendicular P(2)N(2) scaffolds.

PCP-bridged chalcogen-centred anions: coordination chemistry and carbon-based reactivity.

Since the discovery of the stabilising influence of thiophosphinoyl groups in methanediides by Le Floch et al. (Angew. Chem.

S,C,S-Pnictogen bonding in pincer complexes of the methanediide [C(Ph2PS)2](2-).

The metathetical reactions of Li(2)[C(Ph(2)PS)(2)] with MCl(3) (M = Sb, Bi) in a 1:1 molar ratio in toluene afford the complexes {MCl[C(Ph(2)PS)(2)]}(2), which dimerise through weak MS interactions; the S,C,S-coordination of the tridentate ligand to the metal in the monomeric units incorporates a polar M-C single bond and a three-centre two-electron S-M-S bond.

Coordination polymers containing ferrocene backbone. Synthesis, structure and electrochemistry.

The reaction of 1,1'-ferrocenedicarboxylic acid (LH(2)) with bis(triphenyltin) oxide afforded a molecular heterobimetallic compound [(Ph(3)Sn)(2)L]. In the latter the two carboxylate units of [L](2-) are involved in an anisobidentate chelating coordination mode to two triphenyl tin units. The reaction of LH(2) with trimethyltin hydroxide or bis(tri-n-butyltin) oxide afforded 2D-coordination polymers [(Me(3)Sn)(2)L](n) and [(n-Bu(3)Sn)(2)L](n) which are formed as a result of anisobidentate bridging coordination action of the two carboxylate units of [L](2-).

Halide-capped tellurium-containing macrocycles.

The reaction of 1,1,2,3,3-pentamethyltrimethylenephosphinic acid (cycPO(2)H) with bis(p-methoxyphenyl)tellurium dichloride (1) affords a 12-membered macrocycle [((p-MeOC(6)H(4))(2)Te)(2)(mu-O)(mu-cycPO(2))(mu(4)-Cl)](2) x C(6)H(6) (2) in good yield. The latter reacts with sodium iodide to give [((p-MeOC(6)H(4))(2)Te)(2)(mu-O)(mu-cycPO(2))(mu(4)-I)](2) x 4 C(6)H(6) (3). 2 and 3 are isostructural dicationic macrocycles and contain a Te(4)P(2)O(6) framework.

Tellurasiloxane cages containing Te(6)Si(4)O(12) and Te(6)Si(6)O(15) frameworks.

Reaction of the silanetriol t-BuSi(OH)(3) with (p-Me(2)NC(6)H(4))(2)TeO in a 4:6 ratio resulted in the formation of [((p-Me(2)NC(6)H(4))(2)Te)(6)(t-BuSiO(3))(4)].1.5 C(7)H(8) (1.