作为一种环境友好的合成工具,通过 CO 键活化与芳基醚的交叉偶联反应引起了广泛的兴趣。然而,CO 键的功能化主要限于镍催化,当一个分子中存在多个 CO 键时,选择性一直是一个突出的挑战。我们在这里报告了第一个铬催化的芳基醚与格氏试剂通过 CO(烷基)键断裂的选择性交叉偶联反应。在室温下使用简单、廉价的铬 (II) 预催化剂结合亚氨基助剂实现了多种转化。它为高效和选择性地构建官能化芳香醛提供了新途径。
Catalytic Oxidative Cyclization of 2′-Arylbenzaldehyde Oxime Ethers under Photoinduced Electron Transfer Conditions
作者:Julie L. Hofstra、Brittany R. Grassbaugh、Quan M. Tran、Nicholas R. Armada、H. J. Peter de Lijser
DOI:10.1021/jo502324z
日期:2015.1.2
sequence is initiated by an electron transfer step followed by nucleophilicattack of the aryl ring onto the nitrogen of the oxime ether. A concave downward Hammett plot is presumably the result of a change in charge distribution in the radical cation species with strongly electron-donating substituents that yields a less electrophilic nitrogenatom and a decreased amount of cyclized product. The reaction
Palladium-Catalyzed Cycloisomerization of 2-Ethynylbiaryls to 9-Methylidene Fluorenes
作者:Hongyu Guo、Sheng Zhang、Xiujuan Feng、Xiaoqiang Yu、Yoshinori Yamamoto、Ming Bao
DOI:10.1021/acs.orglett.2c00534
日期:2022.4.15
presence of weak acid at low temperature to afford 9-methylidene fluorenes in satisfactory to high yields. This new type of cycloisomerization of 2-ethynylbiaryls is operationally simple and scalable and exhibits high functional-group tolerance. Various synthetically useful functional groups, such as halogen atoms, as well as formyl, acetyl, methoxycarbonyl, cyano, and nitro groups, remain intact during
The present invention relates to certain novel benzylamine derivatives, to processes for their preparation, to pharmaceutical formulations containing them and to their use in medical therapy, particularly in the treatment of depression.
functionalized benzaldehydes under mild conditions. This reaction was promoted specifically by a low-cost and simple CrCl2 salt used as a precatalyst, enabling synchronous activations of ortho-C(aryl)–SMe and ortho′-C(aryl)–H bonds to achieve difunctionalization of benzaldimines. This work provided a strategy for accessing arylated, alkylated, and diarylated benzaldehydederivatives as a result of
<i>ipso</i>-Cyclization of unactivated biaryl ynones leading to thio-functionalized spirocyclic enones
作者:Chada Raji Reddy、Uprety Ajaykumar、Amol D. Patil、Remya Ramesh
DOI:10.1039/d3ob00974b
日期:——
Ceric ammonium nitrate (CAN)-promoted oxidative ipso-cyclization of unactivated biaryl ynones with S-centered radicals (SCN/SCF3) to access spiro[5,5]trienones has been established. This approach displayed excellent regioselectivity towards spirocyclization and tolerated a variety of functional groups. Dearomatization of hitherto unknown aryl/heteroaryl groups is also disclosed. DMSO is employed as