Rhodium arylimido/arylamido ring reactions: Electrophilic additions

Journal Article · Tue Jan 05 23:00:00 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), Journal Name: Inorganic Chemistry; (United States) Vol. 32:1; ISSN 0020-1669; ISSN INOCAJ
• Country of Publication: United States
• Language: English

Related Subjects

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