Syntheses, rearrangements, and structural analyses of unsaturated nitrogen donor ligands derived from diphenyldiazomethane and the chiral rhenium Lewis acid [(η-CH)Re(NO)(PPh)].

Diphenyldiazomethane and a labile chlorobenzene complex of [(η-CH)Re(NO)(PPh)] BF react to give the η adduct [(η-CH)Re(NO)(PPh)(NNCPh)] BF (73%). When this is conducted in the presence of copper powder, a 3-phenyl-1-indazole complex derived from carbon-hydrogen bond activation, [(η-CH)Re(NO)(PPh)(NC(Ph)CCHCHCHCHCNH)] BF, is obtained (65%). Subsequent reaction with NaOCH gives indazolyl complex (η-CH)Re(NO)(PPh)(NCCHCHCHCHCC(Ph)N) (85%), derived from NH deprotonation and a 1,2-rhenium shift.

Synthesis, structure, and reactivity of palladacycles that contain a chiral rhenium fragment in the backbone: New cyclometalation and catalyst design strategies.

The bromocyclopentadienyl complex [(eta5-C5H4Br)Re(CO)3] is converted to racemic [(eta5-C5H4Br)Re(NO)(PPh3)(CH2PPh2)] (1 b) similarly to a published sequence for cyclopentadienyl analogues. Treatment of enantiopure (S)-[(eta5-C5H5)Re(NO)(PPh3)(CH3)] with nBuLi and I2 gives (S)-[(eta5-C5H4I)Re(NO)(PPh3)(CH3)] ((S)-6 c; 84 %), which is converted (Ph3C+ PF6 -, PPh2H, tBuOK) to (S)-[(eta5-C5H4I)Re(NO)(PPh3)(CH2PPh2)] ((S)-1 c). Reactions of 1 b and (S)-1 c with Pd[P(tBu)3]2 yield [{(eta5-C5H4)Re(NO)(PPh3)(mu-CH2PPh2)Pd(mu-X)}2] (10; X = b, Br, rac/meso, 88 %; c, I, S,S, 22 %).

New approaches to high-activity transition-metal catalysts for carbon-carbon bond forming reactions. Rhenium-containing phosphorus donor ligands for palladium-catalyzed Suzuki cross-couplings.

The rhenium complexes (eta 5-C5H5)Re(NO)(PPh3)((CH2)nPR2:) (n/R = 0/Ph, 0/t-Bu, 0/Me, 1/Ph, 1/t-Bu), which contain electron-rich and sterically congested phosphido moieties, give active catalysts for the title reaction; typical conditions (toluene, 60-100 degrees C): aryl bromide (1.0 equiv.), PhB(OH)2 (1.