已经提出了一种直接闭环策略,该策略涉及用于合成苯并 [ b ] 氮卓类化合物的o -炔基苯胺衍生物的不太容易进行 7-内切-挖掘碳环化。由于氮的高亲核性,在 o -炔基苯胺衍生物中的微不足道的 5-内切环化已被克服,通过在金催化下使用它们的插烯酰胺来获得广泛的苯并[ b ]]azepines 以原子经济的方式具有出色的官能团相容性。氘加扰实验和 DFT 研究支持一种机制,该机制涉及通过关键的环丙基金卡宾中间体稳定最初形成的七元乙烯基金中间体的构象变化及其随后由抗衡阴离子介导的原脱氧反应。
Hendrickson Reagent Induced Rearrangement of Aryl Propargyl Alcohols To α,β-Unsaturated Aldehydes
作者:Ziad Moussa、Ateyatallah Aljuhani
DOI:10.2174/1570178615666180329154246
日期:2018.8.8
solution (2 mL), followed by the addition of water and Et3N (2.0 mmol) and further stirring at room temperature for 1h. Subsequent workup with 5% NaHCO3 (20 mL) and purification afforded α,β- unsaturated aldehydes. Eighteen aryl propargyl alcohol substrates with a terminal α-acetylenic group were transformed in good to excellent yields (71-85%) to enals. The methodology proved successful with secondary
Diversity-Oriented Synthesis Based on the DPPP-Catalyzed Mixed Double-Michael Reactions of Electron-Deficient Acetylenes and β-Amino Alcohols
作者:Yi Chiao Fan、Ohyun Kwon
DOI:10.3390/molecules16053802
日期:——
opane (DPPP)-catalyzed mixed double-Michael reactions of β-amino alcohols with electron-deficient acetylenes. These reactions are very suitable for the diversity-oriented parallel syntheses of oxizolidines because: (i) they are performed under mild metal-free conditions and (ii) the products are isolated without complicated work-up. To demonstrate the applicability of mixed double-Michael reactions
with azomethineimines has successfully been developed under mild reaction conditions, affording biologically interesting tetrahydropyrazoloisoquinoline derivatives in high to excellent yields and with excellent stereoselectivity. The reaction follows a tandem [3+2] cycloaddition/allylation/elimination of AcOH pathway. Allenyl carbinol acetates also reacted well with in situ generated azomethine imine
Gold-Catalyzed Regioselective Hydration of Propargyl Acetates Assisted by a Neighboring Carbonyl Group: Access to α-Acyloxy Methyl Ketones and Synthesis of (±)-Actinopolymorphol B
作者:Nayan Ghosh、Sanatan Nayak、Akhila K. Sahoo
DOI:10.1021/jo101995g
日期:2011.1.21
suitable to perform hydration of TMS-substituted propargyl acetates, even though it requires prolonged reaction time for completion. Stereointegrity of the propargylic acetate is preserved during the hydration. The robustness of the system is successfully demonstrated through gram scale preparation of the product in nearly quantitative yield. The common α-acyloxy methylketone is transformed to 1,2-diol
Sequential Gold-Catalyzed Carbene Transfer/Ring Closure: Oxidative Cyclization of β-(2-Alkynylphenyl)-α,β-ynones to Indenofuranones
作者:Navnath Rode、Fabio Marinelli、Antonio Arcadi、Tapas Adak、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/adsc.201801082
日期:2018.12.21
β‐(2‐Alkynylphenyl)‐α,β‐ynones undergo a gold‐catalyzedoxidative two‐fold cyclization in the presence of N‐oxides to give 1,3‐disubstituted‐8H‐indeno[1,2‐c]furan‐8‐ones in good yields. This cascade process is triggered by a selective oxygen transfer from an N‐oxide onto the gold‐activated alkynone to generate a α‐dioxocarbene intermediate which, via carbene transfer across the remaining alkyne moiety