- Rhoda-Electrocatalyzed Bimetallic C?H Oxygenation by Weak O-Coordination
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Rhodium-electrocatalyzed arene C?H oxygenation by weakly O-coordinating amides and ketones have been established by bimetallic electrocatalysis. Likewise, diverse dihydrooxazinones were selectively accessed by the judicious choice of current, enabling twofold C?H functionalization. Detailed mechanistic studies by experiment, mass spectroscopy and cyclovoltammetric analysis provided support for an unprecedented electrooxidation-induced C?H activation by a bimetallic rhodium catalysis manifold.
- Tan, Xuefeng,Massignan, Leonardo,Hou, Xiaoyan,Frey, Johanna,Oliveira, Jo?o C. A.,Hussain, Masoom Nasiha,Ackermann, Lutz
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p. 13264 - 13270
(2021/05/06)
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- C?H Oxygenation Reactions Enabled by Dual Catalysis with Electrogenerated Hypervalent Iodine Species and Ruthenium Complexes
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The catalytic generation of hypervalent iodine(III) reagents by anodic electrooxidation was orchestrated towards an unprecedented electrocatalytic C?H oxygenation of weakly coordinating aromatic amides and ketones. Thus, catalytic quantities of iodoarenes in concert with catalytic amounts of ruthenium(II) complexes set the stage for versatile C?H activations with ample scope and high functional group tolerance. Detailed mechanistic studies by experiment and computation substantiate the role of the iodoarene as the electrochemically relevant species towards C?H oxygenations with electricity as a sustainable oxidant and molecular hydrogen as the sole by-product. para-Selective C?H oxygenations likewise proved viable in the absence of directing groups.
- Massignan, Leonardo,Tan, Xuefeng,Meyer, Tjark H.,Kuniyil, Rositha,Messinis, Antonis M.,Ackermann, Lutz
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supporting information
p. 3184 - 3189
(2020/01/24)
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- Synthesis of functionalized carbamates and quinones via sequential oxidation of salicylaldehydes using TBHP as the oxidant
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A sequential oxidative approach was designed to functionalize salicylaldehyde derivatives and provide corresponding bi-functional amide-carbamate and amide-quinone units. A combination of metal/metal free conditions and TBHP as the external oxidant provid
- Rajendra Prasad,Suresh,Ravikumar,Reddy, N. Veera,Reddy, K. Rajender
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supporting information
p. 6307 - 6310
(2014/12/10)
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- Ruthenium-catalyzed oxidative C(sp2)-H bond hydroxylation: Site-selective C-O bond formation on benzamides
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Well-defined ruthenium carboxylate complexes enabled unprecedented ruthenium-catalyzed C(sp2)-H hydroxylations on benzamides with PhI(OAc)2 as the oxidant at a remarkably low catalyst loading of 1.0 mol %.
- Thirunavukkarasu, Vedhagiri S.,Hubrich, Jonathan,Ackermann, Lutz
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supporting information; experimental part
p. 4210 - 4213
(2012/10/08)
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- Synthesis of tertiary amides from anionically activated aromatic trifluoromethyl groups
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Figure presented In this paper, a novel synthesis of tertiary amides from anionically activated aromatic trifluoromethyl groups is presented. Anionically activated trifluoromethyl groups react with secondary amines under aqueous conditions to afford tertiary amides. The mechanism involves initial elimination of hydrogen fluoride by an E1cB mechanism to afford an electrophilic quinone methide- or azafulvene-type intermediate that reacts with secondary amines under aqueous conditions to afford the tertiary amide in good yield (up to 99%).
- OMahony, Gavin,Pitts, Andrew K.
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supporting information; experimental part
p. 2024 - 2027
(2010/06/21)
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- Anionic ortho-fries rearrangement, a facile route to arenol-based mannich bases
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Phenol and 1-naphthol-based carbamates undergo the anionic ortho-Fries rearrangement to their corresponding amides. Bulky substitution at position 8 of 1-naphthol-based carbamates makes the rearrangement an exclusive reaction, even at -90 C, under a variety of conditions. The amides can be efficiently reduced to the corresponding Mannich bases. A novel route to 7-[(dialkylamino)methyl]-8- hydroxy-1-naphthaldehydes is presented.
- Assimomytis, Nikos,Sariyannis, Yiannis,Stavropoulos, Georgios,Tsoungas, Petros G.,Varvounis, George,Cordopatis, Paul
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experimental part
p. 2777 - 2782
(2010/03/03)
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- ISOQUINOLINE-5-SULFONIC ACID AMIDES AS INHIBITORS OF AKT (PROTEIN KINASE B)
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The present invention relates to compounds Formula (I): as inhibitors of AKT activity, which are useful for the treatment of susceptible neoplasms and viral infections.
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- Effects of mixed H2O-CH3CN solvents on the Bronsted coefficient for the intramolecular general base-catalyzed cleavage of ionized phenyl salicylate in the presence of primary and secondary amines
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Nucleophilic second-order rate constants, knms, for the reactions of several primary and secondary amines with ionized phenyl salicylate (PS-) show a nonlinear decrease with the increase in the content of CH3CN from 2 to ≤50% v/v in mixed aqueous solvent. The values of knms remain almost unchanged with the change in the content of CH3CN at >50% v/v. The nucleophilic reactivity of primary and secondary amines toward PS- reveal Bronsted plots of different Bronsted coefficients, βnuc, at a constant content of CH3CN in mixed aqueous solvents. The values of βnuc decrease from 0.4 to nearly 0 for primary amines and from 0.22 to 0.12 for secondary amines with the increase in CH3CN content from 2 to 70% v/v. The values of knms/kMeOHms (where kMeOHms represents the nucleophilic second-order rate constant for the reaction of MeOH with PS- in H2O-CH3CN solvents), obtained within 2-50% v/v CH3CN, fit to an empirical equation: log (knms/kMeOHms) = θ+λX where X is the % v/v content of CH3CN, and θ and λ are empirical constants. It has been shown empirically that both θ and λ are the function of Bronsted coefficient βlg. The values of λ are used to calculate βlg and these βlg values for all amines except Tris lie within -0.32 to -0.46. The effects of mixed water-acetonitrile solvents on pKa of leaving the group, phenol, and conjugate acid of amine nucleophile have been concluded to be the major source for the observed solvent effects on knms. The βlg for Tris is unusually very close to zero.
- Khan, M. Niyaz,Arifin,George,Wahab
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p. 153 - 164
(2007/10/03)
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- Solvent effect on intramolecular general base-catalysed aminolysis of ionized phenyl salicylate
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The nucleophilic second-order rate constants (k1) for the reactions of ionized phenyl salicylate (PS-) with primary and secondary amines in 70percent (v/v) ethanol-water reveal Bronsted plots of slopes βnuc1 = 0.32 +/- 0.10 and βnuc2 = 0.22 +/- 0.02, respectively.Different Bronsted slopes obtained for the reactions of PS- with primary and secondary amines suggest the occurrence of different locations of the transition state in the critical rate-determining step.The change in water content from 99.2 to 70percent (v/v) in EtOH-H2O causes reduction in k1 by ca. 3-fold for all the amines studied.Ionization constants of all the protonated amines turn out to be larger in 70percent (v/v) EtOH-H2O than in pure water.
- Khan, Mohammad Niyaz,Suraio, Yusuf M.,Musa, Aminu I.,Mohammad, Abubakar A.,Gambo, Saratu L.
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p. 752 - 757
(2007/10/02)
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- Intramolecular General Base Catalysis and the Rate-determining Step in the Nucleophilic Cleavage of Ionized Phenyl Salicylate with Primary and Secondary Amines
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The nucleophilic second-order rate constants for the reactions of ionized phenyl salicylate (PS-) with primary and secondary amines have revealed Broensted plots of slopes βnuc1 = 0.52+/-0.06 and βnuc2 = 0.27+/-0.05, respectively.The suggested stepwise reaction mechanism involves the intramolecular proton transfer from cationic nitrogen to the anionic phenolic oxygen to form the monoanionic tetrahedral addition intermediate as the rate-determining step.The low value of βnuc2 is attributed to the extensive of proton transfer in the late transition state while the large value of βnuc1 is ascribed to the proton transfer in the early transition state of the rate-determining step.However, these low and high values of βnuc2 and βnuc1, respectively, are also compatible with the occurence of respective early and late transition states in the rate-determining step involving concerted intramolecular general base-catalysed nucleophilic attack at the carbonyl carbon of PS-.Significantly large positive deviations from Broensted plots have been observed for the reactivities of α-nucleophiles toward PS-.Monoprotonated ethane-1,2-diamine is ca. 20-fold more reactive than would be expected from its basicity, and this is attributed to the occurence of the intramolecular general acid catalysis.The reactions of PS- with hydroxylamine and N-methylhydroxylamine involve ca. >/=70 percent aminolysis and -.
- Khan, Mohammad Niyaz
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p. 199 - 208
(2007/10/02)
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