65492-21-9Relevant academic research and scientific papers
The Photochemical Activity of a Halogen-Bonded Complex Enables the Microfluidic Light-Driven Alkylation of Phenols
Cuadros, Sara,Rosso, Cristian,Barison, Giorgia,Costa, Paolo,Kurbasic, Marina,Bonchio, Marcella,Prato, Maurizio,Filippini, Giacomo,Dell'Amico, Luca
supporting information, p. 2961 - 2966 (2022/05/02)
A mild light-driven protocol for the direct alkylation of phenols is reported. The process is driven by the photochemical activity of a halogen-bonded complex formed upon complexation of the in situ generated electron-rich phenolate anion with the α-iodosulfone. The reaction proceeds rapidly (10 min) under microfluidic conditions, delivering a wide variety of ortho-alkylated products (27 examples, up to 97% yield, >20:1 regioselectivity, on a gram scale), including densely functionalized bioactive phenol derivatives.
Forskolin Editing via Radical Iodo- A nd Hydroalkylation
Pruteanu, Elena,Tappin, Nicholas D. C.,G?rbu, Vladilena,Morarescu, Olga,Dénès, Fabrice,Kulci?ki, Veaceslav,Renaud, Philippe
supporting information, p. 1247 - 1261 (2021/01/21)
The modification of highly oxygenated forskolin as well as manoyl and epi-manoyl oxide, two less functionalized model substrates sharing the same polycyclic skeleton, via intermolecular carbon-centered radical addition to the vinyl moiety has been investigated. Highly regio- A nd reasonably stereoselective iodine atom transfer radical addition (ATRA) reactions were developed. Unprotected forskolin afforded an unexpected cyclic ether derivative. Protection of the 1,3-diol as an acetonide led the formation of the iodine ATRA product. Interestingly, by changing the mode of initiation of the radical process, in situ protection of the forskolin 1,3-diol moiety as a cyclic boronic ester took place during the iodine ATRA process without disruption of the radical chain process. This very mild radical-mediated in situ protection of 1,3-diol is expected to be of interest for a broad range of radical and non-radical transformations. Finally, by using our recently developed tert-butyl?-catechol-mediated hydroalkylation procedure, highly efficient preparation of forskolin derivatives bearing an extra ester or sulfone group was achieved.
Methyl Radical Initiated Kharasch and Related Reactions
Tappin, Nicholas D. C.,Renaud, Philippe
supporting information, p. 275 - 282 (2020/12/07)
An improved procedure to run halogen atom and related chalcogen group transfer radical additions is reported. The procedure relies on the thermal decomposition of di-tert-butylhyponitrite (DTBHN), a safer alternative to the explosive diacetyl peroxide, to produce highly reactive methyl radicals that can initiate the chain process. This mode of initiation generates byproducts that are either gaseous (N2) or volatile (acetone and methyl halide) thereby facilitating greatly product purification by either flash column chromatography or distillation. In addition, remarkably simple and mild reaction conditions (refluxing EtOAc during 30 minutes under normal atmosphere) and a low excess of the radical precursor reagent (2 equivalents) make this protocol particularly attractive for preparative synthetic applications. This initiation procedure has been demonstrated with a broad scope since it works efficiently to add a range of electrophilic radicals generated from iodides, bromides, selenides and xanthates over a range of unactivated terminal alkenes. A diverse set of radical trap substrates exemplifies a broad functional group tolerance. Finally, di-tert-butyl peroxyoxalate (DTBPO) is also demonstrated as alternative source of tert-butoxyl radicals to initiate these reactions under identical conditions which gives gaseous by-products (CO2). (Figure presented.).
Controlled α-mono- and α,α-di-halogenation of alkyl sulfones using reagent-solvent halogen bonding
Poteat, Christopher M.,Lindsay, Vincent N. G.
supporting information, p. 2912 - 2915 (2019/03/17)
The direct and selective α-mono-bromination of alkyl sulfones was achieved through base-mediated electrophilic halogenation. The appropriate combination of solvent and electrophilic bromine source was found to be critical to control the nature of the products formed, where reagent-solvent halogen bonding is proposed to control the selectivity via alteration of the effective size of the electrophilic bromine source. Conversely, the α,α-di-brominated sulfones were selectively obtained in good yields following polyhalogenation followed by selective de-halogenation during workup. Both procedures can be applied on gram scale, and the mono-halogenation was successfully extended to the fully selective α-chlorination, α-iodination and α-fluorination of alkyl sulfones.
Enantioselective Formal α-Methylation and α-Benzylation of Aldehydes by Means of Photo-organocatalysis
Filippini, Giacomo,Silvi, Mattia,Melchiorre, Paolo
supporting information, p. 4447 - 4451 (2017/04/13)
Detailed herein is the photochemical organocatalytic enantioselective α-alkylation of aldehydes with (phenylsulfonyl)alkyl iodides. The chemistry relies on the direct photoexcitation of enamines to trigger the formation of reactive carbon-centered radicals from iodosulfones, while the ground-state chiral enamines provide effective stereochemical control over the radical trapping process. The phenylsulfonyl moiety, acting as a redox auxiliary group, facilitates the generation of radicals. In addition, it can eventually be removed under mild reducing conditions to reveal methyl and benzyl groups.
Practical synthesis of β-oxo benzo[d]thiazolyl sulfones: Scope and limitations
Pospiil, Jii,Robiette, Raphael,Sato, Hitoshi,Debrus, Kevin
supporting information; experimental part, p. 1225 - 1234 (2012/03/07)
In this paper, we discuss our new synthetic approach towards functionalized benzo[d]thiazolyl (BT) sulfones, based on the reunion of alkyl BT sulfones and various electrophiles (e.g. R-CO-X, RO-CO-X, RS-CO-X, Ts-X...). All important aspects of this coupling reaction, including relevant and undesirable side reactions, are evaluated by means of calculations and competitive experiments. The scope and limitations of this method are established. The Royal Society of Chemistry 2012.
Chemoselective mono halogenation of β-keto-sulfones using potassium halide and hydrogen peroxide; synthesis of halomethyl sulfones and dihalomethyl sulfones
Suryakiran,Prabhakar,Srikanth Reddy,Chinni Mahesh,Rajesh,Venkateswarlu
, p. 877 - 881 (2007/10/03)
The synthesis of α-halo β-keto-sulfones using potassium halide and hydrogen peroxide as a chemoselective mono halogenation reagent and the synthesis of α,α-symmetrical and asymmetrical dihalo β-keto-sulfones and α-halo, α-alkyl and β-keto-sulfones is described. Base induced cleavage of α-halo β-keto-sulfones, α,α-dihalo β-keto-sulfones, and α-halo, α-alkyl β-keto-sulfones afforded the corresponding halomethyl sulfones, dihalomethyl sulfones and haloalkyl sulfones.
Synthesis of α-iodo β-ketosulfones and α-iodo methylsulfones using iodine monochloride
Suryakiran,Srikanth Reddy,Suresh,Lakshman,Venkateswarlu
, p. 4319 - 4323 (2007/10/03)
The synthesis of α-iodo β-ketosulfones and α-iodo methylsulfones is described. Reaction of β-ketosulfones with iodine monochloride in acetic acid at room temperature gave the corresponding α-iodo β-ketosulfones, which, on treatment with aqueous alkali, un
An Efficient Synthesis of α-Iodo Derivatives of Sulfones, Sulfoximines, and Phosphine Oxides
Imamoto, Tsuneo,Koto, Hiroyasu
, p. 982 - 983 (2007/10/02)
1-Iodoalkyl sulfones are prepared by conversion of alkyl sulfones into 1-sulfonylalkyltriethylalanates by reaction with butyllithium and triethylalane and subsequent reaction with iodine.The same method can be applied to the conversion of methyldiarylphos
