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.
Pd(II)/Cu(II)-Catalyzed Regio- and Stereoselective Synthesis of (<i>E</i>)-3-Arylmethyleneisoindolin-1-ones Using Air as the Terminal Oxidant
作者:So Won Youn、Tae Yun Ko、Young Ho Kim、Yun Ah Kim
DOI:10.1021/acs.orglett.8b03409
日期:2018.12.21
Regio- and stereoselective synthesis of (E)-3-arylmethyleneisoindolin-1-ones via Pd(II)/Cu(II)-catalyzedone-pot C–C/C–N bond forming sequence between amides and styrenes is reported. This method provides facile and rapid access to a diverse range of such compounds using readily available starting materials under mild aerobic conditions with good functional group tolerance and high selectivity and efficiency
<scp>Pd‐Catalyzed</scp>
Asymmetric Synthesis of 3,
<scp>4‐Dihydroisoquinolinones</scp>
From
<scp>
<i>N</i>
‐Ts‐Benzamides
</scp>
and 1,
<scp>3‐Dienes</scp>
作者:Tae Kyun Kim、So Won Youn
DOI:10.1002/bkcs.12227
日期:2021.3
A Pd(II)‐catalyzed asymmetric oxidative annulation of N‐Ts‐benzamides with 1,3‐dienes using a chiral pyridine‐oxazoline‐type ligand for the regio‐ and stereoselective synthesis of chiral 3,4‐dihydroisoquinolinones has been developed.
Direct Acyl Substitution of Carboxylic Acids: A Chemoselective O- to N-Acyl Migration in the Traceless Staudinger Ligation
作者:Andrew D. Kosal、Erin E. Wilson、Brandon L. Ashfeld
DOI:10.1002/chem.201201773
日期:2012.11.5
chlorophosphite‐modified, Staudinger‐like acylation of azides involving a highly chemoselective, direct nucleophilic acyl substitution of carboxylicacids is described. The reaction provides the corresponding amides with analytical purity in 32–97 % yield after a simple aqueous workup without the need for a pre‐activation step. The use of chlorophosphites as dual carboxylic acid–azide activating agents
N-Sulfonyl acetylketenimine as a highly reactive intermediate for synthesis of N-Aroylsulfonamides
作者:Weiguang Yang、Dayun Huang、Xiaobao Zeng、Jianlan Zhang、Xinyan Wang、Yuefei Hu
DOI:10.1016/j.tet.2018.12.005
日期:2019.1
A highlyreactiveintermediate N-sulfonyl acetylketenimine was generated from an ynone-participated CuAAC/ring-opening method. Its unique structure allowed it to react with aryl carboxylic acids to give N-aroylsulfonamides via a novel Mumm-type rearrangement.