Addition of Aromatic C−H Bonds to η³-Allenyl/Propargyl Complexes. Organoplatinum-Induced Electrophilic Aromatic Substitution Reactions

Addition of Aromatic C−H Bonds to η3-Allenyl/Propargyl Complexes. Organoplatinum-Induced Electrophilic Aromatic Substitution Reaction

Well-Controlled Block Polymerization/Copolymerization of Alkenes and/or Carbon Monoxide by Cationic Palladium Methyl Complexes

Cationic palladium imine−phosphine complexes [Pd(P−N)(CH3)(CH3CN)]+ catalyze the living block polymerization and copolymerization of olefins and/or carbon monoxide. The palladium-capped polymers, intermediates of the polymerization, were isolated

Reactivity of Octahedral η¹-Allenyl Iridium toward Hard Nucleophiles^†

A labile octahedral (η1-allenyl)iridium complex, (OC-6-42)-Ir(Cl)(PPh3)2(OTf)(CO)(η1-CHCCH2) (2a), undergoes regioselective addition with water or alcohol at the allenyl central carbon to generate the (η3-2-hydroxyallyl) and (η3-2-alkoxyallyl)iridium complexes {Ir(Cl)-(PPh3)2(CO)[η3-CH2C(OR)CH2]}(OTf) (R = H (3), Me (4a), Et (4b)), respectively. The complex 3 and the η3-oxa-TMM species Ir(Cl)(PPh3)2(CO)[η3-CH2C(O)CH2] (5) constitutes a conjugate acid−base pair. Hydrolysis of the η3-alkoxyallyl complexes yields 3, which further transforms into the carbon-bound iridium enolate (OC-6-52)-{Ir(Cl)(PPh3)2(OH2)(CO)[η1-CH2C(O)CH3]}(OTf) (6). The reaction of 2a with ammonia results in the substitution of NH3 for the triflate ligand instead of hydroamination to the allenyl ligand. The construction of the C−N bond, however, is alternatively achieved by replacing the alkoxy group in 4a or 4b with the amino group, leading to the formation of the N-protonated and N-alkylated η3-aza-TMM iridium {Ir(Cl)(PPh3)2(CO)[η3-CH2C(NR2)CH2]}(OTf) (R = H (7a), Et (7b))

Four- and Five-Coordinate Aluminum Ketiminate Complexes: Synthesis, Characterization, and Ring-Opening Polymerization

A series of aluminum complexes featuring with the ketiminate ligand, OCMeCHCMeNHAr (Ar = 2,6-iPr2C6H3, 1), have been prepared and characterized spectroscopically and structurally. Reactions of 1 with trialkylaluminum in 1:1 or 1:2 molar ratio generate four- and five-coordinated aluminum complexes (OCMeCHCMeNAr)AlR2 (R = Me (2); R = Et (3)) and (OCMeCHCMeNAr)2AlR (R = Me (4); R = Et (5)) in high yields. Similarly, reaction of AlCl3 with 1 or 2 equiv of the lithiated 1 in toluene afforded bis(ketiminate) aluminum chloride complex, (OCMeCHCMeNAr)2AlCl (6) or (OCMeCHCMeNAr)AlCl2 (7). Surprisingly, reacting 6 with 1 equiv of AgBF4 in methylene/acetonitrile mix-solvents generates (OCMeCHCMeNAr)2AlF (8) in moderate yield. The structures of complexes 2−6 and 8 have been determined by X-ray crystallography. Complexes 2 and 3 both exhibit tetrahedron structures with the aluminum atom surrounded by oxygen and nitrogen atoms of chelating ketiminate and two alkyl groups. The mono- and bis-ketiminate aluminum complexes 2−5 have shown moderate activity toward the ring-opening polymerization of ε-caprolactone

Regioselective Attack of a Soft Carbon Nucleophile and Hydrogen Sulfide at the Central Carbon of a β-Substituted η³-Allyl To Respectively Form η³-TMM and New Metallacyclic Thiacyclobutane Complexes^†

The cationic β-substituted allyl complexes {Pt(PPh3)2[η3-CH2C(OE)CH2]}+ (E = silyl, alkyl, acyl) undergo the substitution of the carbon nucleophile for OE at the allyl central carbon to transform into η3-TMM complexes or undergo addition by hydrogen sulfide to yield new metallathiacyclobutane complexes

Coordination of Aniline to an (η¹-Allenyl)iridium Complex Leading to Hydroanilination^†

Formation of the N-arylated η3-aza-TMM complexes of iridium from regioselective hydroanilination of an octahedral (η1-allenyl)iridium complex has been studied. (OC-6-42)-Ir(Cl)(PPh3)2(OTf)(CO)(η1-CHCCH2) (2) undergoes the substitution of L (L = NH3, NH2NH2, MeNH2, EtNH2, iPrNH2, PhCH2NH2) for the triflate ligand to yield {(OC-6-42)-Ir(Cl)(PPh3)2(L)(CO)(η1-CHCCH2)}(OTf) (3d−i). In contrast, the reactions of 2 with XC6H4NH2 (X = F, NO2, MeO, H, Me), Ph2NH, and Ph(Me)NH result in regioselective addition at the allenyl ligand, thereby generating the N-arylated η3-aza-TMM complexes 5a−g. The mechanistic studies confirm that the hydroanilination is preceded by the formation of an aniline-ligated intermediate

Four- and Five-Coordinate Aluminum Ketiminate Complexes: Synthesis, Characterization, and Ring-Opening Polymerization

A series of aluminum complexes featuring with the ketiminate ligand, OCMeCHCMeNHAr (Ar = 2,6-iPr2C6H3, 1), have been prepared and characterized spectroscopically and structurally. Reactions of 1 with trialkylaluminum in 1:1 or 1:2 molar ratio generate four- and five-coordinated aluminum complexes (OCMeCHCMeNAr)AlR2 (R = Me (2); R = Et (3)) and (OCMeCHCMeNAr)2AlR (R = Me (4); R = Et (5)) in high yields. Similarly, reaction of AlCl3 with 1 or 2 equiv of the lithiated 1 in toluene afforded bis(ketiminate) aluminum chloride complex, (OCMeCHCMeNAr)2AlCl (6) or (OCMeCHCMeNAr)AlCl2 (7). Surprisingly, reacting 6 with 1 equiv of AgBF4 in methylene/acetonitrile mix-solvents generates (OCMeCHCMeNAr)2AlF (8) in moderate yield. The structures of complexes 2−6 and 8 have been determined by X-ray crystallography. Complexes 2 and 3 both exhibit tetrahedron structures with the aluminum atom surrounded by oxygen and nitrogen atoms of chelating ketiminate and two alkyl groups. The mono- and bis-ketiminate aluminum complexes 2−5 have shown moderate activity toward the ring-opening polymerization of ε-caprolactone

Four- and Five-Coordinate Aluminum Ketiminate Complexes: Synthesis, Characterization, and Ring-Opening Polymerization

A series of aluminum complexes featuring with the ketiminate ligand, OCMeCHCMeNHAr (Ar = 2,6-iPr2C6H3, 1), have been prepared and characterized spectroscopically and structurally. Reactions of 1 with trialkylaluminum in 1:1 or 1:2 molar ratio generate four- and five-coordinated aluminum complexes (OCMeCHCMeNAr)AlR2 (R = Me (2); R = Et (3)) and (OCMeCHCMeNAr)2AlR (R = Me (4); R = Et (5)) in high yields. Similarly, reaction of AlCl3 with 1 or 2 equiv of the lithiated 1 in toluene afforded bis(ketiminate) aluminum chloride complex, (OCMeCHCMeNAr)2AlCl (6) or (OCMeCHCMeNAr)AlCl2 (7). Surprisingly, reacting 6 with 1 equiv of AgBF4 in methylene/acetonitrile mix-solvents generates (OCMeCHCMeNAr)2AlF (8) in moderate yield. The structures of complexes 2−6 and 8 have been determined by X-ray crystallography. Complexes 2 and 3 both exhibit tetrahedron structures with the aluminum atom surrounded by oxygen and nitrogen atoms of chelating ketiminate and two alkyl groups. The mono- and bis-ketiminate aluminum complexes 2−5 have shown moderate activity toward the ring-opening polymerization of ε-caprolactone

Four- and Five-Coordinate Aluminum Ketiminate Complexes: Synthesis, Characterization, and Ring-Opening Polymerization

A series of aluminum complexes featuring with the ketiminate ligand, OCMeCHCMeNHAr (Ar = 2,6-iPr2C6H3, 1), have been prepared and characterized spectroscopically and structurally. Reactions of 1 with trialkylaluminum in 1:1 or 1:2 molar ratio generate four- and five-coordinated aluminum complexes (OCMeCHCMeNAr)AlR2 (R = Me (2); R = Et (3)) and (OCMeCHCMeNAr)2AlR (R = Me (4); R = Et (5)) in high yields. Similarly, reaction of AlCl3 with 1 or 2 equiv of the lithiated 1 in toluene afforded bis(ketiminate) aluminum chloride complex, (OCMeCHCMeNAr)2AlCl (6) or (OCMeCHCMeNAr)AlCl2 (7). Surprisingly, reacting 6 with 1 equiv of AgBF4 in methylene/acetonitrile mix-solvents generates (OCMeCHCMeNAr)2AlF (8) in moderate yield. The structures of complexes 2−6 and 8 have been determined by X-ray crystallography. Complexes 2 and 3 both exhibit tetrahedron structures with the aluminum atom surrounded by oxygen and nitrogen atoms of chelating ketiminate and two alkyl groups. The mono- and bis-ketiminate aluminum complexes 2−5 have shown moderate activity toward the ring-opening polymerization of ε-caprolactone

Four- and Five-Coordinate Aluminum Ketiminate Complexes: Synthesis, Characterization, and Ring-Opening Polymerization

A series of aluminum complexes featuring with the ketiminate ligand, OCMeCHCMeNHAr (Ar = 2,6-iPr2C6H3, 1), have been prepared and characterized spectroscopically and structurally. Reactions of 1 with trialkylaluminum in 1:1 or 1:2 molar ratio generate four- and five-coordinated aluminum complexes (OCMeCHCMeNAr)AlR2 (R = Me (2); R = Et (3)) and (OCMeCHCMeNAr)2AlR (R = Me (4); R = Et (5)) in high yields. Similarly, reaction of AlCl3 with 1 or 2 equiv of the lithiated 1 in toluene afforded bis(ketiminate) aluminum chloride complex, (OCMeCHCMeNAr)2AlCl (6) or (OCMeCHCMeNAr)AlCl2 (7). Surprisingly, reacting 6 with 1 equiv of AgBF4 in methylene/acetonitrile mix-solvents generates (OCMeCHCMeNAr)2AlF (8) in moderate yield. The structures of complexes 2−6 and 8 have been determined by X-ray crystallography. Complexes 2 and 3 both exhibit tetrahedron structures with the aluminum atom surrounded by oxygen and nitrogen atoms of chelating ketiminate and two alkyl groups. The mono- and bis-ketiminate aluminum complexes 2−5 have shown moderate activity toward the ring-opening polymerization of ε-caprolactone