Cross-conjugated bifunctional species including a phosphine, phosphine oxide, phosphine sulfide, phosphonium salt, phosphorus ylide and a gold(I) phosphine complex have been prepared. The photophysical characteristics of the series of compounds have been determined experimentally and are discussed/compared with simpler analogues lacking cross-conjugated branches and rationalized on the basis of...

The reaction of [Re(H)(NO)2(PR3)2] complexes (1 a: R = PCy3; 1 b: R = PiPr3) with [H(OEt2)2][BAr(F)4] ([BAr(F)4] = tetrakis{3,5-bis(trifluoromethyl)phenyl}borate) in benzene at room temperature gave the corresponding cations [Re(NO)2(PR3)2][BAr(F)4] (2 a and 2 b). The addition of phenyldiazomethane to benzene solutions of 2 a and 2 b afforded the moderately stable cationic rhenium(I)-benzyliden...

A highly efficient Ullmann homocoupling reaction of aryl halides using palladium (II) phosphine-ylide complexes as homogenous pre-catalysts under aerobic conditions has been developed without the need for any chemical co‐reducing agents. The procedure is relatively mild and appears to have broad applicability, being useful for the homocoupling of both electron-deficient and electron-rich aryl h...

The Wittig reaction and its variants are the most powerful approaches for constructing carbon-carbon double bonds in organic synthesis due to their unambiguous positioning and good stereoselectivity.1 Of the recent developments,2-4 much attention has been paid to ylide olefination of aldehydes3 and ketones4 under neutral conditions by transition metal complex-catalyzed decomposition of diazo co...

Aryl chalcones rearrange and add methanol to give substituted propane-1-ones upon UV-A irradiation in the presence of PPh3. We propose two possible mechanisms for this photo-rearrangement. The reaction involves either the formation of a phosphine-carbonyl intermediate, nucleophilic addition of MeOH and 1,2-aryl migration or the formation of ylide and carbene intermediates. The intermediates tra...

The ylide-functionalized diisopropyl phosphine (prYPhos) promotes Pd-catalyzed Suzuki-Miyaura couplings of aryl chlorides and bromides with arylboronic acids. Using Pd2(dba)3/prYPhos as the catalyst K2CO3 base, various (hetero)biaryls were synthesized in 45–98% yields at mild reaction conditions, tolerating sensitive functional groups steric hindrance. electron rich, sterically demanding ligand...

From our investigations on phosphine-catalyzed [4+2] annulations between α-alkyl allenoates and activated olefins for the synthesis of cyclohexenes, we discovered a hexamethylphosphorous triamide (HMPT)-catalyzed [4+2] reaction between α-alkyl allenoates 1 and arylidene malonates or arylidene cyanoacetates 2 that provides highly functionalized cyclohexenes 3 and 4 in synthetically useful yields...

Ab initio calculations are presented for several species containing a silicon-phosphorus bond. The types of bonding studied include "normal" single, double, and triple bonds, as well as an ylide-like structure. The latter is found to be much less strongly bound than the carbon analogue, with a smaller stretching force constant than that in silylphosphine. The insertions of silylene into the pho...

Inter and intramolecular interactions are important in the context of conformational preferences, molecular reactivity and supramolecular chemistry. The extent of 1, 4 PO intramolecular interaction present in the solid state structures of a special class of phosphine appended phosphorus ylide ligand and its Hg(II) derivatives were examined. While halogen ligands around mercury ion seem to affec...

Rhodium(I) complexes of the hybrid ylide-phosphine ligands, Ph2P(CH2)nPPh2(CHC(O)C6H5) (n = 1: dppm-yl, or 2: dppe-yl) have been synthesised from [Rh(μ-Cl)(COD)]2 (COD = 1,5-cyclooctadiene) and characterized by NMR spectroscopic and X-ray structural methods. The dppe-yl behaves as an ambidentate ligand; it functions as a monodentate P-donor ligand with a dangling ylidic carbon in the neutral ch...