Photoactuators based on the dynamic molecular crystals of naphthalene acrylic acids driven by stereospecific [2+2] cycloaddition reactions
作者:Jiaxi Liu、Kaiqi Ye、Yanbing Shen、Jiang Peng、Jingbo Sun、Ran Lu
DOI:10.1039/c9tc06689f
日期:——
needle-like crystals of 1FNaAA, and the slice-like crystals of 1ClNaAA and 1BrNaAA show bending, cracking, coiling, rotating and twisting triggered by 365 nm light. It is found that stereospecific [2+2] cycloadditionreactions take place in the crystals to afford one stereoisomer of β-type cyclobutanes, since 1FNaAA, 1ClNaAA, 1BrNaAA and 6BrNaAA pack in a head-to-head mode, which satisfies the Schmidt's
Syntheses of benz[f]indoles from 1, 2-disubstituted naphthalene derivatives by means of cyclization reactions were attempted. The Fischer indolization of 1-methyl-(5a), 1-chloro-(5b), or 1-nitro-(5c)-2-naphthylhydrazones gave only benz[e]indole derivative or decomposed products, and the desired 9-substituted benz[f]indole (3) was not produced. On the other hand, the Fischer indolization of 2-methoxy-1-naphthylhydrazone (17) gave ethyl 5-chlorobenz[g]indole-2-carboxylate (19). The hemetsberger reaction of 1-methyoxy-2-naphthylazido acrylate (26a) gave an azirine (28a) and a nitrile (29a), whereas the same reaction of 1-chloro-2-naphthylazido acrylate (26b) gave the desired 4-chlorobenz[f]indole in a poor yield together with large amounts of by-products, the azirine (28b), the nitrile (29b) and the benz[g]indole (20). These results show that cyclization reactions of a 2-substituent toward the 3-position in naphthalene derivative are not suitable for preparing benz[f]indoles.
Cascade C-C and C-N Bond Formation: A Straightforward Synthesis of Phenanthridines and Fused Quinolines
作者:Ashwini Borah、Pranjal Gogoi
DOI:10.1002/ejoc.201600220
日期:2016.4
Pd-catalyzed cascade process has been developed for the synthesis of quinoline and phenanthridine derivativesfrom various β-chloro α,β-unsaturatedaldehydes and 2-chloroaryl aldehydes, respectively, in good to high yields. The reaction proceeds through Pd-catalyzed cascade carbon–carbon and carbon–nitrogen bond formation in a single reaction vessel. The requisite β-chloro α,β-unsaturatedaldehydes were efficiently
The metal‐free amination of different aldehydes is catalyzed by hypoiodite, which is generated by employing commercially available sodium percarbonate as the co‐oxidant. This approach has several advantages: it is a metal‐free oxidation that works under mild reaction conditions; furthermore, it has a wide substrate scope and does not give toxic by‐products from the co‐oxidant that is used.
Nickel‐Catalyzed Enantioconvergent Carboxylation Enabled by a Chiral 2,2′‐Bipyridine Ligand
作者:Linghua Wang、Tao Li、Saima Perveen、Shuai Zhang、Xicheng Wang、Yizhao Ouyang、Pengfei Li
DOI:10.1002/anie.202213943
日期:2022.12.19
An enantioselective carboxylation reaction using CO2 has been demonstrated as efficient for the synthesis of chiral carboxylic acids including profen family anti-inflammatory drugs. The reaction takes place under atmospheric pressure and benefits from mild conditions using nickel-catalysis in combination with a chiral 2,2′-bipyridine ligand, namely Me-Sbpy.
使用 CO 2的对映选择性羧化反应已被证明可有效合成手性羧酸,包括普罗芬家族抗炎药。该反应在大气压力下进行,并受益于使用镍催化结合手性 2,2'-联吡啶配体(即 Me-Sbpy)的温和条件。