Tin for organic synthesis. 10. Unconventional regiospecific syntheses of aromatic carbonamides and thiocarbonamides by means of tin-mediated Friedel-Crafts reactions
摘要:
Friedel-Crafts reactions of stannylarenes 1 with tosyl isocyanate (TsNCO, 2) give N-tosylcarbonamides 3 via ipso substitution of the stannyl group. Thus, unconventionally substituted aromatic carbonamides can be obtained. The combination of the reaction of 1 and 2 with that of 1 and chlorosulfonyl isocyanate (14) allows one-pot syntheses of N-(arylsulfonyl)-substituted aromatic carbonamides with optional substitution patterns on both aromatic rings. The known ipso-specific substitutions of stannylarenes with 14 are extended to bi- and tricyclic arenes as well as to thiophenes 6 and 22. One stannyl group can serve as a leaving group for two aromatic systems, as shown with diaryldialkyltins 29. Also, stannylalkanes such as 27 react with 14 to afford alkylsulfonyl isocyanates and products of further reactions, such as 28. From the reactions of 1 with ethoxycarbonyl isothiocyanate (32), ortho- and meta-substituted aromatic thiocarbonamides 33 which are potential precursors for further syntheses, are accessible. The scope, limitations, and mechanism of these electrophilic substitutions are outlined.
Co-Catalyzed Synthesis of <i>N</i>-Sulfonylcarboxamides from Carboxylic Acids and Sulfonyl Azides
作者:Yue Fang、Zheng-Yang Gu、Shun-Yi Wang、Jin-Ming Yang、Shun-Jun Ji
DOI:10.1021/acs.joc.8b01300
日期:2018.8.17
A Co-catalyzed effective synthesis of N-sulfonylcarboxamides from the reaction of carboxylicacids and organic azides in the presence of isocyanide has been developed. The protocol has the advantages of short time, low temperature, and being oxidant-free, which provides a new and simple approach for the synthesis of N-sulfonylcarboxamides in good to excellent yields with a broad substrate scope.
Controllable construction of isoquinolinedione and isocoumarin scaffolds <i>via</i> Rh<sup>III</sup>-catalyzed C–H annulation of <i>N</i>-tosylbenzamides with diazo compounds
An efficient protocol for the synthesis of isoquinolinediones by RhIII-catalyzed C–H activation/annulation/decarboxylation of N-tosylbenzamides with diazo compounds is reported.
Metal-free C–H Activation over Graphene Oxide toward Direct Syntheses of Structurally Different Amines and Amides in Water
作者:Prashant Shukla、Ambika Asati、Smita R. Bhardiya、Manorama Singh、Vijai K. Rai、Ankita Rai
DOI:10.1021/acs.joc.0c02219
日期:2020.12.4
Unprecedented metal-free synthesis of a variety of amines and amides is reported via amination of C(sp3)–H and C(sp2)–H bonds. The strategy involves graphene-oxide/I2-catalyzed nitrene insertion using PhINTs as a nitrene (NT) source in water at room temperature. A wide range of structurally different substrates, viz., cyclohexane, cyclic ethers, arenes, alkyl aromatic systems, and aldehydes/ketones
据报道,通过胺化C(sp 3)–H和C(sp 2)–H键,空前合成了多种胺和酰胺。该策略涉及在室温下使用PhINTs作为水中的腈(NT)源使用氧化石墨烯/ I 2催化的腈插入。尽管具有较低的收率,但已成功地使用各种结构不同的底物,即环己烷,环醚,芳烃,烷基芳族体系和具有α-苯环的醛/酮,以高收率获得了相应的腈插入产物在少数情况下。所设想的方法在操作简便性,无金属催化,使用水作为溶剂,环境反应条件和催化剂的可重复使用性方面均优于其他方法。
Ruthenium-Catalyzed Synthesis of Isoindolinones via Amide-Directed Addition of Aromatic C-H Bonds to Aldimines
Straightforward Route! [RuCl2(p‐cymene)]2 promoted amide‐directed hydroarylation of aldimines in the presence of a catalytic amount of base gives the corresponding isoindolinone derivatives. A variety of amides and saldimines participated in the present Ru‐catalyzed reaction to furnish the corresponding isoindolinones in moderate to high yield. A variety of amides and aldimines participated in the
Ruthenium(II) oxidase catalysis by direct dioxygen‐coupled turnover enabled step‐economical oxidative CH alkenylation reactions at ambient pressure. Versatile ruthenium(II) biscarboxylate catalysts displayed ample substrate scope and proved applicable to weaklycoordinating and removable directing groups. The twofold CH functionalization strategy was characterized by exceedingly mild reaction conditions