Reactivity of Metallophosphide Anions with Electrophilic (Arene)tricarbonylmetal Complexes

Abstract

Reaction of metallophosphide anions [(CO)xM′PPh2]− (M′ = Cr, Fe) with neutral tricarbonyl(η6‐fluoroarene)chromium and cationic (η6‐arene)tricarbonylmanganese complexes give rise to the formation of dinuclear complexes. These complexes are obtained either by substitution of the fluoride anion in the (arene)chromium complexes, or by addition to the ring in the (arene)manganese complexes. The X‐ray structure of one homodimetallic (Cr−Cr) complex was obtained and compared with its solution structure. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Catalytic Asymmetric C–H Arylation of (η6-Arene)Chromium Complexes: Facile Access to Planar-Chiral Phosphines

“…With this in mind, we envisaged that the process could be rendered asymmetric in the presence of a chiral phosphine ligand suitable for distinguishing between the two enantiotopic C–H bonds of a prochiral complex. Furthermore, the presence of a C–F bond in the aromatic core should allow for the subsequent easy transformation of the resulting products into chiral arylphosphine derivatives via phosphination …”

“…Furthermore, the presence of a C−F bond in the aromatic core should allow for the subsequent easy transformation of the resulting products into chiral arylphosphine derivatives via phosphination. 28 We started our investigation testing similar conditions to those reported for the (nonasymmetric) ortho-arylation of (fluorobenzene)Cr(CO) 3 (1a) complexes 26a as a benchmark for reactivity. Under these conditions good reactivity was observed with 41% of racemic monoarylated product 3aa and 31% of bisarylated 4aa formed (Table 1, entry 1).…”

Phosphines and Related Tervalent Phosphorus Systems

“…Among a considerable range of new monophosphines obtained by trichlorosilane reduction, usually in the final step of the synthesis, are the phosphorus core conjugated triaryl-dendrimer unit (111), 250 a range of triarylphosphines bearing branched fluoroalkyl moieties ('split pony tails'), e.g., (112), 251 and a variety of chiral monophosphines, including the phosphinocarboxylic acid (113), 252 phosphinoaryloxathianes, e.g., (114), 253 a series of axially chiral ortho-aminoarylphosphines, e.g., (115) 254,255 and (116), 256 the axially chiral binaphthylphosphine (117), 257 and the chiral arylferrocenylphosphines (118). 258 Trichlorosilane reduction has also been used in the synthesis of phosphino- [6]-and - [7]-helicenes, e.g., (119), which are also chiral systems, 259,260 and a variety of other chiral diphosphines, including the spiro system (120), 261 the C 2 -symmetric cyclobutane system (121), 262 and the tetraphenylene (122). 263 In addition, many new chiral 2,2 0 -diphosphinobiphenyls have been described, including 'SYNPHOS' (123, X¼CH 2 CH 2 ) 264,265 and 'DIFLUORPHOS' (123, X¼CF 2 ), 266,267 the related system (124), 268 and others involving simple alkoxy substituents in the biphenyl system 269 and bulky aryl groups at phosphorus.…”

“…Metallophosphides have also been shown to displace a variety of groups bound to the arene rings of arene-chromium and -manganese complexes to form the related phosphinoarene systems. 122 Acylphosphines are among the products of the reactions of lithium dialkylphosphides with benzocyclobutenone chromium complexes. 123 Lithium mono(organo)phosphide reagents have been shown to add to fulvenes to give the phosphinoalkylsubstituted cyclopentadienides (63), subsequently used in the synthesis of catalytically-active constrained geometry titanium-and zirconium-metallocene complexes.…”

Synthesis and Application in Catalysis of Planar Chiral (η5-Cyclohexadienyl)tricarbonylmanganese-Based Ligands

“…To our knowledge, up to now, very few η 5 complexes substituted by a PPh 2 function have been synthesized. The introduction of a phosphinyl group at the sp 3 C 6 carbon of the cyclohexadienyl unit, which is located exo to the Mn(CO) 3 tripod, has been realized by addition of PPh 2 Li onto the cationic (η 6 -benzene)Mn(CO) 3 + complex (complex A , Figure ). Two other phosphine derivatives, with the phosphinyl substituent localized on the C 1 carbon (complexes B ) or on the C 2 carbon (complex C ) of the cyclohexadienyl moiety, were obtained from a chloro-substituted precursor by a palladium-catalyzed cross-coupling procedure for B or from a bromo derivative by a halogen–metal exchange reaction for C .…”