通过钯(II)催化的分子内合成-羟基钯/烯烃插入/ sp 2 -C–H键活化直接访问9-Chloro-1 H-苯并[ b ]呋喃[3,4- e ]氮杂-1-酮级联
摘要:
建立了一种有效的Pd(II)催化级联方法,用于从具有侧链α的N-炔丙基芳基胺开始合成9-氯-1 H-苯并[ b ]呋喃[3,4- e ]氮杂-1-酮,β-不饱和酯支架。该顺序过程的机制涉及分子内的顺氧基palpalation,随后的烯烃插入和邻位sp 2 -C-Cl键形成反应。这种高原子和步长经济的级联序列在一次合成操作中产生了两个杂环和三个新键。
通过钯(II)催化的分子内合成-羟基钯/烯烃插入/ sp 2 -C–H键活化直接访问9-Chloro-1 H-苯并[ b ]呋喃[3,4- e ]氮杂-1-酮级联
摘要:
建立了一种有效的Pd(II)催化级联方法,用于从具有侧链α的N-炔丙基芳基胺开始合成9-氯-1 H-苯并[ b ]呋喃[3,4- e ]氮杂-1-酮,β-不饱和酯支架。该顺序过程的机制涉及分子内的顺氧基palpalation,随后的烯烃插入和邻位sp 2 -C-Cl键形成反应。这种高原子和步长经济的级联序列在一次合成操作中产生了两个杂环和三个新键。
Intramolecular iminium ene reaction with Cu(I) catalysts: facile formation of 4-amino-3-methylenechromans from O-propargyl salicylaldehydes and dialkylamines
作者:Noriyoshi Arai、Takeshi Ohkuma
DOI:10.1016/j.tet.2011.01.007
日期:2011.3
Reaction of O-propargyl salicylaldehyde and related compounds with dialkylamines in the presence of copper(I) iodide gave 4-(alkylamino)-3-methylenechroman derivatives in good yields through the loss of one alkyl group of the dialkylamine. The reaction also worked well by employing 2-amino benzaldehyde derivatives to afford 4-(alkylamino)-3-methylene-1,2,3,4-tetrahydroquinolines. A deuterium-labeling experiment suggested that the a-hydrogen of the dialkylamine was transferred intramolecularly into the terminal methylene. This result indicated the reaction mechanism, which involved the formation of iminium ion between the aldehyde and the dialkylamine followed by ene-type C-C bond formation with inverse electron demand and hydrolysis. (C) 2011 Elsevier Ltd. All rights reserved.