New Three-Component Glyoxylation-Decarbonylative Stille Coupling Sequence to Acyl Heterocycles under Mild Conditions
作者:Thomas Müller、Boris Tasch、Eugen Merkul、Walter Frank
DOI:10.1055/s-0029-1218802
日期:2010.7
A consecutive sequence of glyoxylation of 1-methyl-1H-indole, 1-(4-methoxybenzyl)-1H-pyrrolo[2,3-b]pyridine or N-substituted pyrroles with oxalyl chloride and subsequent decarbonylative Stille coupling under very mild, Lewis acid free conditions using all reactants in equimolar quantities is reported. As an illustration, this glyoxylation-decarbonylative couplingsequence was elaborated into a consecutive
1-甲基-1 H-吲哚,1-(4-甲氧基苄基)-1 H-吡咯并[2,3- b ]吡啶或N-取代的吡咯与草酰氯的乙氧基化连续序列,随后在非常低的温度下进行脱羰Stille偶联报道了使用所有等摩尔量反应物的温和,无路易斯酸条件。作为说明,该乙氧基化-脱羰基偶联序列被精加工为1-甲基-3-(1-甲基-4,5-二氢-1 H-吡唑-3-基)-1 H的连续四组分合成-吲哚 乙醛酸化-脱羰基Stille反应-多组分反应-CC偶联-酰基杂环
Regiospecific <i>C</i>-Acylation of Pyrroles and Indoles Using <i>N</i>-Acylbenzotriazoles
作者:Alan R. Katritzky、Kazuyuki Suzuki、Sandeep K. Singh、Hai-Ying He
DOI:10.1021/jo034187z
日期:2003.7.1
Reactions of pyrrole (2) or 1-methylpyrrole (4) with readily available N-acylbenzotriazoles 1a-g (RCOBt, where R = 4-tolyl, 4-nitrophenyl, 4-diethylaminophenyl, 2-furyl, 2-pyridyl, 2-indolyl, or 2-pyrrolyl) in the presence of TiCl(4) produced 2-acylpyrroles 3a-g and 5a-g in good to excellent yields. 1-Triisopropylsilylpyrrole (6) under the same conditions gave the respective 3-acylpyrroles 7a-g. Similarly
The concept of this process is to form a C–N bond through the three-component Mannich reaction of aldehydes, amines, and indoles, thereby introducing an aminomethyl group on the indole ring. Next, this system catalyzed the formation of the corresponding imide ion from the Mannich product, followed by rapid hydrolysis to give the final C-3 carbonyl indole product. More than 30 indole C-3 acylated products
Reported herein is an effective strategy for oxidative cross-coupling of indoles with various aldehydes. The strategy is based on a two-step transformation via a well-known Mannich-type reaction and a C–N bond cleavage for carbonyl introduction. The key step—the C–N bond cleavage of the Mannich product—was enabled by electrochemistry. This strategy (with over 40 examples) ensures excellent functional-group