- Amide Effects in C?H Activation: Noncovalent Interactions with L-Shaped Ligand for meta Borylation of Aromatic Amides
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A new concept for the meta-selective borylation of aromatic amides is described. It has been demonstrated that while esters gave para borylations, amides lead to meta borylations. For achieving high meta selectivity, an L-shaped bifunctional ligand has been employed and engages in an O???K noncovalent interaction with the oxygen atom of the moderately distorted amide carbonyl group. This interaction provides exceptional control for meta C?H activation/borylation.
- Bisht, Ranjana,Hoque, Md Emdadul,Chattopadhyay, Buddhadeb
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supporting information
p. 15762 - 15766
(2018/11/10)
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- Para-Selective Alkylation of Benzamides and Aromatic Ketones by Cooperative Nickel/Aluminum Catalysis
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We report a method that ensures the selective alkylation of benzamides and aromatic ketones at the para-position via cooperative nickel/aluminum catalysis. Using a bulky catalyst/cocatalyst system allows reactions between benzamides and alkenes to afford the corresponding para-alkylated products. The origin of the high para-selectivity has also been investigated by density functional theory calculations.
- Okumura, Shogo,Tang, Shuwei,Saito, Teruhiko,Semba, Kazuhiko,Sakaki, Shigeyoshi,Nakao, Yoshiaki
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supporting information
p. 14699 - 14704
(2016/11/18)
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- Directed ortho metalation of n,n-diethyl benzamides. Methodology and regiospecific synthesis of useful contiguously tri- and tetra-substituted oxygenated aromatics, phthalides and phthalic anhydrides
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Full experimental details for the directed ortho metalation approch to a variety of simple ortho-substituted N,N-diethyl benzamides (Table 1) and contiguously 1,2,3- and 1,2,3,4-substituted benzamides (Tables 2) are given. The efficient conversion of these benzamides (6, 10, 12, 13, 18, 19) into phthalides (9a-b, 16b-c, 17) and phthalic anhydrides (8,16a), compounds previously available by demanding, classical methods, is detailed. A short synthesis of iso-ochracinic acid (27) is described.
- De Silva,Reed,Billedeau,Wang,Norris,Snieckus
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p. 4863 - 4878
(2007/10/02)
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- 1-Amino-2-phthalimido-diazene-1-oxides: Formation, Properties and Fragmentation Reactions into Imido- and Amino-nitrenes
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Oxidatively generated phthalimido-nitrene (1) reacts with the nitrosoamines 2a-d (see Scheme 1) to give the corresponding (Z)-1-amino-2-phthalimido-diazene-1-oxides 3a-d in good yields.With the O-nitroso compound 2e, no addition of the nitrene 1 took place.The constitution of the adducts 3 (R = NR2') is deduced from their spectroscopic properties (UV., IR., 1H-NMR. and MS.) as compared to those of (Z)-1-aryl- and (Z)-1-alkyl-2-phthalimido-diazene-1-oxides 3 (R = aryl and alkyl, resp.).The (Z)-configuration of 3 (R = NR2') follows from an X-ray analysis wich is reported separately.Compounds 3 (R = NR2') are cleaved photolytically as well as by acid to the corresponding nitrosoamines 2 (R = NR2') and the nitrene 1, which could be trapped by cyclohexene to give 40percent of 7-phthalimido-7-azabicycloheptane (8) and by dimethylsulfoxide to yield 96percent of S,S-dimethyl-N-phthalimido-sulfoximide (13).Nucleophilic attack leads to fragmentation of 3 (R = NR2') into derivatives of phthalic acid and degradation products of intermediate aminonitrenes 24 corresponding to the respective nitrosoamines 2 (R = NR2') with loss of oxygen.A general rationalization for the formation of 24 includes as a key step a N-to C-migration of the O-atom (see Scheme 6).The final fate of 24 is depending of the type of the nucleophile used.Thus, hydrazinolysis of 3b and of 3c generates besides N,N'-phthalohydrazine (15), morpholine (14) from 3b and 1,3-dihydroisoindole (16) together with 6'-methylidene-1,2,3,4-tetrahydronaphthalene-2-spiro-1'-cyclohexa-2',4'-diene (17) from 3c (see Scheme 5).Treatment of 3b and of 3c with sodium methylate leads in both reactions to monomethyl phthalate (33) and, with 3b, to1,2-dimorpholinodiazene (31) and, with 3c, to 17 (see Scheme 7).Finally, the reaction of 3b with diethylamine generates N,N-diethylphthalamic acid (36), morpholine (14), 1,1,4,4-tetraethyl-2-tetrazene (34) and 1,1-diethyl-4,4-(3-oxapentamethylene)-2-tetrazene (35) (see Scheme 8).
- Hoesch, Lienhard
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p. 890 - 904
(2007/10/02)
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