Electrophilic ipso-Cyclization of N-(p-Methoxyaryl)propiolamides Involving an Electrophile-Exchange Process
摘要:
A novel electrophilic ipso-cyclization involving an electrophile-exchange process has been developed. In the presence of CuX (X = I, Br, SCN) and electrophilic fluoride reagents, a variety of N-(p-methoxyaryl)propiolamides and 4-methoxyphenyl 3-phenylpropiolate were cyclized to selectively afford the corresponding spiro[4.5]decenones in moderate to good yields. It is noteworthy that two azaquaternary tricyclic products were synthesized through a two-step pathway involving an electrophilic ipso-cyclization and then an intramolecular Heck reaction.
Ag-Catalyzed Oxidative <i>ipso</i>-Cyclization via Decarboxylative Acylation/Alkylation: Access to 3-Acyl/Alkyl-spiro[4.5]trienones
作者:Chada Raji Reddy、Dattahari H. Kolgave、Muppidi Subbarao、Mounika Aila、Santosh Kumar Prajapti
DOI:10.1021/acs.orglett.0c01588
日期:2020.7.17
A strategy to functionalized spiro[4.5]trienones, by domino silver-catalyzed decarboxylative acylation or alkylation/ ipso-cyclization of N-arylpropiolamides with α-ketoacids/alkyl carboxylic acids, is presented. This transformation offers a wide range of substituted 3-acyl/alkyl-spiro[4.5]trienones in high yields with a broad substrate scope. The approach was further extended to access fused tricyclic
Visible-Light-Mediated ipso-Carbosulfonylation of Alkynes: Synthesis of 3-Sulfonylspiro[4,5]trienones from Propiolamides and Sulfonyl Chlorides under Transition-Metal-Free Conditions
sulfonylation and ipso-cyclization of alkynes. In this transformation, the O atom in the newly generated carbonyl is derived from H2O and it features a broad substrates scope, especially for alkyl propiolamides and aliphatic sulfonyl chlorides.
已开发出一种高效便捷的合成多种 3-磺酰基螺[4,5] 三烯酮的策略。这种炔烃的同位碳磺酰化在无过渡金属条件下通过可见光催化进行,代表了炔烃的新磺酰化和同位环化。在这种转化中,新生成的羰基中的 O 原子来源于 H2O,它具有广泛的底物范围,特别是对于烷基丙酰胺和脂肪族磺酰氯。
Visible-light promoted one-pot synthesis of sulfonated spiro[4,5]trienones from propiolamides, anilines and sulfur dioxide under transition metal-free conditions
A novel visible-light promoted sulfonylation/ipso-cyclization of N-arylpropiolamides with aromatic amines and DABCO·(SO2)2 to synthesize various sulfonated spiro[4,5]trienones is reported.
Visible-Light-Mediated <i>Ipso</i>-Carboacylation of Alkynes: Synthesis of 3-Acylspiro[4,5]trienones from <i>N</i>-(<i>p</i>-Methoxyaryl)propiolamides and Acyl Chlorides
A novel visible-light-mediated ipso-carboacylation of N-(p-methoxyaryl)propiolamides with acyl chloride has been established for the synthesis of diverse 3-acylspiro[4,5]trienones with high selectivity and efficiency. This method represents a new difunctionalization of alkynes through cross coupling of the acyl chloride C–Cl bonds with an ipso-aromatic carbon by simultaneously forming two new carbon–carbon
A nitrogen-centered radical strategy for the preparation of 3-acylated spiro[4,5]trienones via visible-light-mediated acylation/ipso-cyclization of alkynes with acyl oxime esters is reported. The alkyl- and aryl-substituted acylradicals, which generate from the cleavage of carbon-carbon σ-bonds in acyl oxime esters via nitrogen-centered radical pathway, attack the carbon-carbon triple bonds in propiolamides