Selective Sulfonylation Research Articles

Visible-Light-Promoted Selective Sulfonylation and Selenylation of Dienes to Access Sulfonyl-/Seleno-benzazepine Derivatives.

A novel visible-light-promoted selective sulfonylation and selenylation of dienes with selenosulfonates has been developed. This technology provides mild access to a wide range of sulfonyl benzo[b]azepinones and seleno-benzo[b]azepines. Preliminary mechanistic studies suggest that the sulfonylation involves a sulfonyl radical engaged cascade process, and the selenylation is accomplished through a sequential oxidation/electrophilic cyclization process. The large-scale operation and late-stage modification experiment reveal the promising utility of this protocol.

N-4 Alkyl Cytosine Derivatives Synthesis: A New Approach

The selective N-4 alkylation of cytosine plays a critical role in the synthesis of biologically active molecules. This work focuses on the development of practical reaction conditions toward a regioselective synthesis of N-4-alkyl cytosine derivatives. The sequence includes a direct and selective sulfonylation at the N-1 site of the cytosine, followed by the alkylation of the amino site using KHMDS in CH2Cl2/THF mixture, providing a fast and efficient approach consistent with pyrimidine-based drug design.

Selective sulfonylation and isonitrilation of para-quinone methides employing TosMIC as a source of sulfonyl group or isonitrile group.

Chemoselective sulfonylation and isonitrilation reactions for the divergent synthesis of valuable diarylmethyl sulfones and isonitrile diarylmethanes starting from easy-to-synthesize para-quinone methides (p-QMs) and commercially abundant p-toluenesulfonylmethyl isocyanide (TosMIC) by using respectively zinc iodide and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as catalysts were developed. The distinguishing feature of this method is that TosMIC plays a dual role from the same substrates in the reaction: as a sulfonyl source or as an isonitrile source. The synthetic utility of this protocol was also demonstrated in the synthesis of difluoroalkylated diarylmethane 5 and diarylmethane ketone derivatives 6 and 7, which are important core structures in natural products and medicines.

Total Synthesis of (−)‐Lepadin F based on a Stereoselective Diels–Alder Reaction Controlled by a Ketolactone‐type Dienophile

An efficient approach to the type III lepadin alkaloids (lepadins F and G) has been developed through a key Diels-Alder reaction, in which a novel ketolactone-type dienophile with chiral diol unit is employed to generate the desirable all-cis-trisubstituted cyclohexene with excellent regio- and stereoselectivity control. The subsequent selective sulfonylation of the diol unit followed by SN 2 cyclization under hydrogenation conditions could construct the substituted piperidine ring. By using this approach, (-)-lepadin F is synthesized from ethyl l-lactate for the first time.

Synthesis of (+)‐Epoxydon, (–)‐Phyllostine, (–)‐RKTS 33, and (–)‐Parasitenone Featuring Selective Sulfonylation and Oxirane Ring Closure of Aldol Cyclization Products

Two new synthetic approaches to anhydrogabosines are developed from the polyoxygenated aldol cyclization intermediates, bearing different O‐protecting groups, which were transformed to various gabosine‐type cyclitols. Selective sulfonylation on the required hydroxyl group of the intermediates and the subsequent oxirane ring closure are employed as the key steps in both approaches, by which (+)‐epoxydon, (–)‐phyllostine, (–)‐RKTS 33, and (–)‐parasitenone were synthesized from δ‐d‐gluconolactone.

Regioselective Sulfonylation/Acylation of Carbohydrates Catalyzed by FeCl3 Combined with Benzoyltrifluoroacetone and Its Mechanism Study.

A catalytic amount of FeCl3 combined with benzoyl trifluoroacetone (Hbtfa) (FeCl3/Hbtfa = 1/2) was used to catalyze sulfonylation/acylation of diols and polyols using diisopropylethylamine (DIPEA) or potassium carbonate (K2CO3) as a base. The catalytic system exhibited high catalytic activity, leading to excellent isolated yields of sulfonylation/acylation products with high regioselectivities. Mechanism studies indicated that FeCl3 initially formed [Fe(btfa)3] (btfa = benzoyl trifluoroacetonate) with twice the amount of Hbtfa under basic conditions in the solvent acetonitrile at room temperature. Then, Fe(btfa)3 and two hydroxyl groups of the substrates formed a five- or six-membered ring intermediate in the presence of the base. The subsequent reaction between the cyclic intermediate and a sulfonylation reagent led to the selective sulfonylation of the substrate. All key intermediates were captured in the high-resolution mass spectrometry assay, therefore demonstrating this mechanism for the first time.

Dehydrogenative Aromatization and Sulfonylation of Pyrrolidines: Orthogonal Reactivity in Photoredox Catalysis

AbstractOxidative dehydrogenative aromatization and selective sulfonylation reactions of N‐heterocycles under visible‐light photoredox catalysis were established. The mild reaction conditions make this approach an appealing and versatile strategy to functionalize/oxidize pyrrolidines whereby arylsulfonyl chlorides were identified to be both catalyst regeneration and sulfonylation reagents.

Dehydrogenative Aromatization and Sulfonylation of Pyrrolidines: Orthogonal Reactivity in Photoredox Catalysis.

Oxidative dehydrogenative aromatization and selective sulfonylation reactions of N-heterocycles under visible-light photoredox catalysis were established. The mild reaction conditions make this approach an appealing and versatile strategy to functionalize/oxidize pyrrolidines whereby arylsulfonyl chlorides were identified to be both catalyst regeneration and sulfonylation reagents.

Concise and efficient synthesis of eliglustat

ABSTRACTEliglustat, a ceramide glucosyltransferase inhibitor, was synthesized in six steps with 28.4% overall yield. The key features include the use of a diastereoselective aldol reaction to construct two contiguous stereocenters and a selective sulfonylation of a 1,3-diol catalyzed by dibutyltin oxide.

Micelle-enabled clean and selective sulfonylation of polyfluoroarenes in water under mild conditions

Proline-based designer surfactant FI-750-M has been demonstrated to enable selective nucleophilic aromatic substitution of polyfluoro(hetero)arenes by sulfinate salts in water under mild micellar conditions.

Selective acylation and sulfonylation of 4,6-O-benzylidene-1-deoxy-1-(2-oxo-2-phenylethyl)-β-D-glucopyranose

Selective acylation and sulfonylation of 4,6- O-benzylidene-1-deoxy-1-(2-oxo-2-phenylethyl)-β- D-glucopyranose were systematically studied by intro ducing different electrophiles under the action of catalysts DMAP or Ag 2O. As a result, 18 novel mono-protected compounds at the 2- or 3-position of the C-glucoside were prepared and their structures were confirmed by 1 H-NMR, 13 C-NMR, 2D NOEs and HRMS analysis. The results showed that electrophiles play a significant role in determining the product distrib ution.

ChemInform Abstract: Selective Sulfonylation and Diazotization of Indoles.

AbstractThe metal‐free oxidative coupling of C2,C3‐unsubstituted indoles with arylsulfonylhydrazides proceeds under mild conditions and furnishes difunctionalized indoles with good to excellent yields.

Selective sulfonylation and diazotization of indoles.

A metal-free synthesis of bifunctionalized indole derivatives was developed through a novel TBHP/TBAI-mediated oxidative coupling of C2,C3-unsubstituted indoles with arylsulfonyl hydrazide. Under the same conditions C3-methyl substituted indoles underwent a diazotization process, affording 2-sulfonyldiazenyl-1H-indoles. The former reaction simultaneously established C-S and C-N bonds through selective sulfonylation and diazotization of the indole framework, enabling a mild and practical access to polyfunctionalized indoles with good to excellent yields.

Selective sulfonylation of 4- C-hydroxymethyl-β- l-threo-pento-1,4-furanose: synthesis of bicyclic diazasugars

Hydroxymethylation of α- d-xylo-pentodialdose 6 using excess formaldehyde and sodium hydroxide in THF–water (one pot aldol and crossed Cannizzaro reactions) followed by hydrogenolysis of C3- O-benzyl group afforded triol 8 . The regio-selective α- and β-sulfonylation of hydroxymethyl groups in 8 afforded 9a (α-sulfonylation) and 14 (β-sulfonylation) in good yield. The cleavage of the 1,2-acetonide functionality, individually in 9a and 14 , followed by reaction with 1,3-diaminopropane gave in situ formation of sugar aminals, that undergo concomitant nucleophilic displacement of the sulfonyloxy group by amino functionality to give hitherto unknown bicyclic diazasugars 4 and 5 , respectively, with a hydroxymethyl substituent at C-7.

Selective modification of mono- altro-β-cyclodextrin: dependence of O-sulfonylation position on the shape of sulfonylating reactant

Mono- altro-β-cyclodextrin, which has 21 different hydroxyl groups, was selectively sulfonylated by 2-naphthalenesulfonyl chloride at the 2 A-OH of the altrose residue. By using 1-naphthalenesulfonyl chloride as reactant, the 3 G-OH of the neighboring glucose became available for selective sulfonylation, and the resulted sulfonate was proved to be a very important intermediate for introducing functionalities to the saccharide adjacent to the altroside of mono- altro-β-cyclodextrin that is capable of controlling the orientation of substrate.

Magnesium Perchlorate: An Efficient Catalyst for Selective Sulfonylation of Arenes under Neutral Conditions.

Magnesium perchlorate is found to be an extremely efficient catalyst for the sulfonylation of activated, unactivated and heterocyclic aromatics under almost neutral conditions.

Magnesium Perchlorate: An Efficient Catalyst for Selective Sulfonylation of Arenes under Neutral Conditions

Magnesium perchlorate is found to be an extremely efficient catalyst for the sulfonylation of activated, unactivated and heterocyclic aromatics under almost neutral conditions.

Sodium Periodate Catalyzed Selective Sulfonylation of Aromatics.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Sodium Periodate Catalyzed Selective Sulfonylation of Aromatics

Abstract Sodium periodate catalyzed sulfonylation of aromatics with p-toluenesulfonyl chloride gives the corresponding sulfones in good yield under neutral conditions.

ChemInform Abstract: Selective Sulfonylation of Arenes and Benzoylation of Alcohols Using Lithium Perchlorate as a Catalyst under Neutral Conditions.

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