Author
Pakorn Bovonsombat
Other affiliations: Rockefeller University, Mahidol University, New York University ...read more
Bio: Pakorn Bovonsombat is an academic researcher from Mahidol University International College. The author has contributed to research in topics: Reagent & Halogenation. The author has an hindex of 15, co-authored 52 publications receiving 517 citations. Previous affiliations of Pakorn Bovonsombat include Rockefeller University & Mahidol University.
Topics: Reagent, Halogenation, Halogen bond, Ring (chemistry), Catalysis
Papers published on a yearly basis
Papers
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TL;DR: In this article, a mixed halogenated compound, 2-bromo-4-iodo-1,3,5-trimethylbenzene was prepared in high yield.
Abstract: 1-Bromo-2,5-pyrrolidinedione (NBS) and 1-chloro-2,5-pyrrolidinedione (NCS) with catalytic quantities of p-toluenesulfonic acid have been used for ring halogenations of polyalkylbenzenes. [Hydroxy(tosyloxy)iodo]benzene was effective as a catalyst with NBS but not NCS. Competition experiments with 1-iodo-2,5-pyrrolidinedione (NIS) were run to indicate selectivities in substrates, halogen sources and catalysts. With this information a mixed halogenated compound, 2-bromo-4-iodo-1,3,5-trimethylbenzene was prepared in high yield
66 citations
TL;DR: Mild and highly regioselective monoiodination of phenol and analogues is achieved in high to excellent yields at room temperature with a combination of stoichiometric p-toluenesulfonic acid and N-iodosuccinimide.
42 citations
TL;DR: Para-Regioselective bromination of phenol and analogues, promoted by p-toluenesulfonic acid, is achieved in high to excellent yields at room temperature with N-bromosuccinimide as discussed by the authors.
40 citations
TL;DR: In this article, aryl and alkyl substituted enones were used as templates for aryls and alkynols, using Koser's reagent and N-halosuccinimides to obtain mixed β,β-dihaloenones.
37 citations
TL;DR: In this article, the formation of α-iodoenones from secondary alkynols with NIS/HTIB (cat), tertiary alkynol with I 2 /PDC and enones with I 1 /pyridine have been compared.
33 citations
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TL;DR: One of the goals of this Review is to attract the attention of the scientific community as to the benefits of using hypervalent iodine compounds as an environmentally sustainable alternative to heavy metals.
Abstract: The preparation, structure, and chemistry of hypervalent iodine compounds are reviewed with emphasis on their synthetic application. Compounds of iodine possess reactivity similar to that of transition metals, but have the advantage of environmental sustainability and efficient utilization of natural resources. These compounds are widely used in organic synthesis as selective oxidants and environmentally friendly reagents. Synthetic uses of hypervalent iodine reagents in halogenation reactions, various oxidations, rearrangements, aminations, C–C bond-forming reactions, and transition metal-catalyzed reactions are summarized and discussed. Recent discovery of hypervalent catalytic systems and recyclable reagents, and the development of new enantioselective reactions using chiral hypervalent iodine compounds represent a particularly important achievement in the field of hypervalent iodine chemistry. One of the goals of this Review is to attract the attention of the scientific community as to the benefits of...
1,228 citations
TL;DR: The use of bromine and different bromo-organic compounds in organic synthesis is outlined and the scope of these reagents for various organic transformations such as bromination, cohalogenation, oxidation, cyclization, ring-opening reactions, substitution, rearrangement, hydrolysis, catalysis, etc is described briefly.
Abstract: Bromination is one of the most important transformations in organic synthesis and can be carried out using bromine and many other bromo compounds. Use of molecular bromine in organic synthesis is well-known. However, due to the hazardous nature of bromine, enormous growth has been witnessed in the past several decades for the development of solid bromine carriers. This review outlines the use of bromine and different bromo-organic compounds in organic synthesis. The applications of bromine, a total of 107 bromo-organic compounds, 11 other brominating agents, and a few natural bromine sources were incorporated. The scope of these reagents for various organic transformations such as bromination, cohalogenation, oxidation, cyclization, ring-opening reactions, substitution, rearrangement, hydrolysis, catalysis, etc. has been described briefly to highlight important aspects of the bromo-organic compounds in organic synthesis.
343 citations
TL;DR: 1,1-Dihalo-1-alkenes are valuable synthetic tools in organic chemistry and serve as interesting synthetic intermediates in a variety of non-metal-assisted chemical transformations.
Abstract: 1,1-Dihalo-1-alkenes are valuable synthetic tools in organic
chemistry and serve as interesting synthetic intermediates in a variety of non-metal-assisted chemical transformations. Moreover, the vinyl dihalide functionality is an attractive and versatile bidentate electrophile for organometallic chemistry.
332 citations
TL;DR: DFT calculations suggest that protonated N-halosuccinimides undergo further protosolvation at higher acidities to reactive superelectrophilic species capable of forming a highly reactive and solvated X(+) which would readily react with the aromatic substrates.
Abstract: N-Halosuccinimides (NXS, 1) are efficiently activated in trifluoromethanesulfonic acid and BF(3)-H(2)O, allowing the halogenations of deactivated aromatics. Because BF(3)-H(2)O is more economic, easy to prepare, nonoxidizing, and offers sufficiently high acidity (-H(0) approximately 12, only slightly lower than that of trifluoromethanesulfonic acid), an efficient new electrophilic reagent combination of NXS/BF(3)-H(2)O has been developed. DFT calculations at the B3LYP/6-311++G//B3LYP/6-31G level suggest that protonated N-halosuccinimides undergo further protosolvation at higher acidities to reactive superelectrophilic species capable either in the transfer of X(+) from the protonated forms of NXS to the aromatic substrate or in forming a highly reactive and solvated X(+) which would readily react with the aromatic substrates. Structural aspects of the BF(3)-H(2)O complex have also been investigated.
282 citations
TL;DR: The main features of hypervalent iodine chemistry are presented with an emphasis on recent synthetic applications as mentioned in this paper, and reactions are loosely grouped together according to the type of substrate and/or transformation.
254 citations