Aza-Diels–Alder reaction between N-aryl-1-oxo-1H-isoindolium ions and tert-enamides: Steric effects on reaction outcome

• Amitabh Jha,
• Ting-Yi Chou,
• Zainab ALJaroudi,
• Bobby D. Ellis and
• T. Stanley Cameron

Beilstein J. Org. Chem. 2014, 10, 848–857, doi:10.3762/bjoc.10.81

• -acyliminium cation “diene” was presumably not maintained due to ortho substitution on the N-aryl. This potentially led to misalignment of the orbitals preventing the concerted cycloaddition. Thirdly, it is intriguing to ponder the reasons for the inability of the cationic intermediate to further cyclize with

Oxidative 3,3,3-trifluoropropylation of arylaldehydes

• Akari Ikeda,
• Masaaki Omote,
• Shiho Nomura,
• Miyuu Tanaka,
• Atsushi Tarui,
• Kazuyuki Sato and
• Akira Ando

Beilstein J. Org. Chem. 2013, 9, 2417–2421, doi:10.3762/bjoc.9.279

• substantially. p-Methyl and p-methoxybenzaldehydes gave 3h and 3i in 26% and 17% yield, respectively (Table 2, entries 7 and 8). meta-Substitution of benzaldehyde with a methoxy group gave 3j in 58% yield (Table 2, entry 9). These results are in accordance with the Hammett equation. ortho-Substitution of

Continuous flow photocyclization of stilbenes – scalable synthesis of functionalized phenanthrenes and helicenes

• Quentin Lefebvre,
• Marc Jentsch and
• Magnus Rueping

Beilstein J. Org. Chem. 2013, 9, 1883–1890, doi:10.3762/bjoc.9.221

• also tolerated, but nitro- and amino groups containing stilbenes showed low conversion or decomposition. Meta-substituted substrates gave inseparable regioisomers, and ortho-substitution led to low conversion. In the case of substrate 1e, a separable 1:1 mixture of regioisomers 2e and 2e’ was obtained

Mild and efficient cyanuric chloride catalyzed Pictet–Spengler reaction

• Ashish Sharma,
• Mrityunjay Singh,
• Nitya Nand Rai and
• Devesh Sawant

Beilstein J. Org. Chem. 2013, 9, 1235–1242, doi:10.3762/bjoc.9.140

• cyclized product in poor yield along with impurities [1][22]. In contrast, our methodology proved effective in catalyzing the condensation of tryptamine and electron-donating aldehydes. Interestingly, the ortho-substitution on benzaldehyde is also well tolerated. For instance, the condensation of 2

Synthesis and ring openings of cinnamate-derived N-unfunctionalised aziridines

• Alan Armstrong and
• Alexandra Ferguson

Beilstein J. Org. Chem. 2012, 8, 1747–1752, doi:10.3762/bjoc.8.199

• 4–6, 8, 10). Poor isolated yields were observed when conditions (B) were used on electron-poor substrates; this was attributed to the increased susceptibility to hydrolysis of the aziridine products. The increased steric demand posed by ortho substitution was found to have a detrimental effect on

The effect of the formyl group position upon asymmetric isomeric diarylethenes bearing a naphthalene moiety

• Renjie Wang,
• Shouzhi Pu,
• Gang Liu and
• Shiqiang Cui

Beilstein J. Org. Chem. 2012, 8, 1018–1026, doi:10.3762/bjoc.8.114

• hexane and PMMA films, whereas the molar absorption coefficients of diarylethenes 1–3 increased in order of meta < para < ortho substitution by the formyl group in hexane. The results were in agreement with those of the reported diarylethenes containing an electron-withdrawing cyano group [49], but were