Rhodium arylimido/arylamido ring reactions: Electrophilic additions

Journal Article · Wed Jan 06 00:00:00 EST 1993 · Inorganic Chemistry; (United States)

OSTI ID:7074400

Ge, Yuanwen; Sharp, P R ^[1]

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1. Univ. of Missouri, Columbia (United States)

Tautomeric mixtures of the arylimido/arylamido complexes Rh[sub 2]([mu]-N(4-R-C[sub 6]H[sub 4])(CO)[sub 2]([mu]-dppm)[sub 2]/Rh[sub 2]([mu]-NH(4-R-C[sub 6]H[sub 4]))(CO)[sub 2]([mu]-dppm-H)([mu]-dppm) (1/2) (dppm = bis(diphenylphosphino)methane, dppm-H = bis(diphenylphosphino)methanide) react with carbon-based electrophiles, R[prime]X, to give the arylimido ring addition products [Rh[sub 2]([mu]-N(4,4-R,R[prime]-C[sub 6]H[sub 4]))(CO)[sub 2]([mu]-dppm)[sub 2]][sup +]X[sup [minus]] (3OR,R[prime] = Me, Me; H, Me; Me, Ch[sub 2]Ph; Me, CH[sub 2]Cl; F, CH[sub 2]Ph) (X = Cl, I, OTf)). Crystals of 3 (R, R[prime] = Me, Me; X = Cl)[center dot]CH[sub 2]Cl[sub 2] from CH[sub 2]Cl[sub 2]/ether are monoclinic (C2/c) with a = 37.20 (1) [Angstrom], b = 12.827 (3) [Angstrom], c = 26.497 (6) [Angstrom], [beta] = 97.35 (2)[sup o], V = 12538 [Angstrom][sup 3], d[sub calc] = 1.38 g[center dot]cm[sup [minus]3], and Z = 8. The structure revals an A-frame cationic complex with a quinoid-like group bridging the Rh atoms via the nitrogen atom. Weaker electrophiles with the less nucleophilic 1/2 (R = H) allow other reactions to predominate, giving products resulting from loss of the imido/amido group. Attack of the electrophile at the nitrogen atom of imido tautomer 1 or at the dppm-H ligand of amido tautomer 2 is prevented by the sterically demanding dppm ligand directing the attack to the ring. An interesting ring-to-nitrogen rearrangement of 3 (R, R[prime] = H, Me) is catalyzed by 1/2 via deprotonation to Rh[sub 2]([mu]-N(4-Me-C[sub 6]H[sub 4]))(CO)[sub 2]([mu]-dppm)[sub 2] followed by protonation to the cationic amido complex [Rh[sub 2]([mu]-NH(4-Me-C[sub 6]H[sub 4]))(CO)[sub 2]([mu]-dppm)[sub 2]][sup +]X[sup [minus]]. This rearrangement occurs in the synthesis of 3 (R, R[prime] = H, Me; X = OTf) if a deficiency of MeOTf is used, and high yields of 3 are only obtained with 1 equiv or more of MeOTf. 18 refs., 1 fig., 4 tabs.

• DOE Contract Number: FG02-88ER13880
• OSTI ID: 7074400
• Journal Information: Inorganic Chemistry; (United States), Vol. 32:1; ISSN 0020-1669
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ORGANIC CHLORINE COMPOUNDS
CHEMICAL REACTIONS
RHODIUM COMPLEXES
AMIDES
CARBONYLS
EXPERIMENTAL DATA
IMIDES
LATTICE PARAMETERS
MONOCLINIC LATTICES
X-RAY DIFFRACTION
COHERENT SCATTERING
COMPLEXES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DATA
DIFFRACTION
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
SCATTERING
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties