Maher Khalid | International Islamic University Islamabad (original) (raw)
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Papers by Maher Khalid
Oriental Journal of Chemistry
N-methoxy-N-methyl amides or Weinreb amides are worthy embranchment of amide group and their rich... more N-methoxy-N-methyl amides or Weinreb amides are worthy embranchment of amide group and their rich functional groups in organic synthesis become a strong else unfeasible conversion. Weinreb amides are produced as an intermediate product of the reaction of carboxylic acids, acid chloride or esters with organometallic reagents, which was first uncovered in 1981. The direct conversion of carboxylic acids or acid chlorides or esters to ketones or aldehydes using organometallic reagents do not lead in high yields, because the intermediate ketones are still highly reactive toward the organometallic reagent. However, after derivatization to the corresponding Weinreb Amide, reaction with organometallics does give the desired ketones, as the initial adduct is stabilized and doesn't undergo further reactions. A nucleophilic addition to the Weinreb amides results in a unique and stable five-membered cyclic tetrahedral intermediate which protects the over-addition, leading to a selective con...
Oriental Journal of Chemistry
Oriental Journal of Chemistry
This review highlights recent improvement in trifluoromethylene functionalization processes with ... more This review highlights recent improvement in trifluoromethylene functionalization processes with CF3 reagents, includes: Togni’s, Umemoto’s, CF3SO2Cl, CF3I, Yagupol’skii-Umemoto, TMSCF3, Langlois (CF3SO2Na) and clarifies the several designing to result the corresponding trifluoromethylated products. In this article, the selective trifluoromethylation reactions with Togni’s reagents and their analogs are detailed, which work transition metals or photoactivated Ru or Ir catalysts as single electron giver to yield CF3 radical intermediate species. This issue is to introduce a draft of diverse reports, presenting the modern reaction collect and mechanics produced during the past five years. This task is demanded by the key protocol connected with the trifluoromethylation reactions, designing to sustain researchers a straight forward understanding of such reactions and to award information for further implements.
Asian Journal of Chemistry
This review highlights the most recent syntheses of free radical reactions, which included numero... more This review highlights the most recent syntheses of free radical reactions, which included numerous processes (photoredox catalysis freeradical reactions, free-radical cascade processes reactions, Minisci-type free radical alkylation reactions and metal-catalysis free radical reactions). A photoredox-catalyzed C-H functioning of aromatic heterocyclic utilizing an assortment of various, alkyltrifluoroborates has been mentioned. Utilizing organo-photocatalyst and a moderate oxidant, conditions malleable for functionalizing complex aromatic heterocyclics are outlined to prepare a oriental agent for late-stage derivatization. Radical alkylations of aromatic heterocyclic (Minisci reactions) appear a more direct functionalization of particular, C-H bonds. For the ground mentioned above, alkylation designing using radical have recently risen to significance for the late-stage functionalization of aromatic heterocyclic framework. Therefore, this issue is the primary point of the present survey, which thinks about work from the most recent five years. The work is ordered by the key procedures associated with the synthesis of free-radical reactions, planning to give researchers a simple comprehension of this free radical-reactions-based science and to give bits of knowledge to provide insights for further investigations.
Oriental Journal of Chemistry
N-methoxy-N-methyl amides or Weinreb amides are worthy embranchment of amide group and their rich... more N-methoxy-N-methyl amides or Weinreb amides are worthy embranchment of amide group and their rich functional groups in organic synthesis become a strong else unfeasible conversion. Weinreb amides are produced as an intermediate product of the reaction of carboxylic acids, acid chloride or esters with organometallic reagents, which was first uncovered in 1981. The direct conversion of carboxylic acids or acid chlorides or esters to ketones or aldehydes using organometallic reagents do not lead in high yields, because the intermediate ketones are still highly reactive toward the organometallic reagent. However, after derivatization to the corresponding Weinreb Amide, reaction with organometallics does give the desired ketones, as the initial adduct is stabilized and doesn't undergo further reactions. A nucleophilic addition to the Weinreb amides results in a unique and stable five-membered cyclic tetrahedral intermediate which protects the over-addition, leading to a selective con...
Oriental Journal of Chemistry
Oriental Journal of Chemistry
This review highlights recent improvement in trifluoromethylene functionalization processes with ... more This review highlights recent improvement in trifluoromethylene functionalization processes with CF3 reagents, includes: Togni’s, Umemoto’s, CF3SO2Cl, CF3I, Yagupol’skii-Umemoto, TMSCF3, Langlois (CF3SO2Na) and clarifies the several designing to result the corresponding trifluoromethylated products. In this article, the selective trifluoromethylation reactions with Togni’s reagents and their analogs are detailed, which work transition metals or photoactivated Ru or Ir catalysts as single electron giver to yield CF3 radical intermediate species. This issue is to introduce a draft of diverse reports, presenting the modern reaction collect and mechanics produced during the past five years. This task is demanded by the key protocol connected with the trifluoromethylation reactions, designing to sustain researchers a straight forward understanding of such reactions and to award information for further implements.
Asian Journal of Chemistry
This review highlights the most recent syntheses of free radical reactions, which included numero... more This review highlights the most recent syntheses of free radical reactions, which included numerous processes (photoredox catalysis freeradical reactions, free-radical cascade processes reactions, Minisci-type free radical alkylation reactions and metal-catalysis free radical reactions). A photoredox-catalyzed C-H functioning of aromatic heterocyclic utilizing an assortment of various, alkyltrifluoroborates has been mentioned. Utilizing organo-photocatalyst and a moderate oxidant, conditions malleable for functionalizing complex aromatic heterocyclics are outlined to prepare a oriental agent for late-stage derivatization. Radical alkylations of aromatic heterocyclic (Minisci reactions) appear a more direct functionalization of particular, C-H bonds. For the ground mentioned above, alkylation designing using radical have recently risen to significance for the late-stage functionalization of aromatic heterocyclic framework. Therefore, this issue is the primary point of the present survey, which thinks about work from the most recent five years. The work is ordered by the key procedures associated with the synthesis of free-radical reactions, planning to give researchers a simple comprehension of this free radical-reactions-based science and to give bits of knowledge to provide insights for further investigations.