Cascade radical reaction of substrates with a carbon–carbon triple bond as a radical acceptor

• Hideto Miyabe,
• Ryuta Asada and
• Yoshiji Takemoto

Beilstein J. Org. Chem. 2013, 9, 1148–1155, doi:10.3762/bjoc.9.128

• 17 in 89% yield with 67% ee (Table 2, entry 9). It is also important to note that the high Z/E-selectivity of products was observed even when internal alkynes 14 and 16 were employed. These results indicate that the iodine atom-transfer from R2I to the substituted vinyl radicals proceeded

Gold-catalyzed intermolecular hydroamination of allenes with sulfonamides

• Chen Zhang,
• Shao-Qiao Zhang,
• Hua-Jun Cai and
• Dong-Mei Cui

Beilstein J. Org. Chem. 2013, 9, 1045–1050, doi:10.3762/bjoc.9.117

• the intermolecular hydroamination of allenes with sulfonamides is shown. The reaction proceeded smoothly under mild conditions for differently substituted allenes giving N-allylic sulfonamides in good yields with high regioselectivity and E-selectivity. Keywords: allene; gold catalysis

• efficient hydroamination was realized at rt and led to a 91% yield of 3a with good regioselectivity and high E-selectivity (Table 1, entry 6). Other possible isomers could not be detected. As Ag catalysts, other salts were also screened, AgBF4 was ineffective. With AgSbF6 or AgNTf2, the reaction took place

• took place with exclusive attack of sulfonamide at the more electron-rich allene terminus to afford the corresponding adduct 3m with 68% yield and with high E-selectivity (Table 3, entry 6). In addition, hydroamination of trisubstituted allene 1h took place to afford a different product (Table 3, entry

Microphotochemistry: 4,4'-Dimethoxybenzophenone mediated photodecarboxylation reactions involving phthalimides

• Oksana Shvydkiv,
• Kieran Nolan and
• Michael Oelgemöller

Beilstein J. Org. Chem. 2011, 7, 1055–1063, doi:10.3762/bjoc.7.121

• acetone-sensitized procedure, the DMBP mediated reaction of N-methylphthalimide (2) and potassium phenylacetate (8) furnished the corresponding phenylmethyleneisoindolinone 10 with high E-selectivity (Scheme 5; Table 2), as determined by comparison with literature data. In acetone-d6, the olefinic proton

An efficient and practical entry to 2-amido-dienes and 3-amido-trienes from allenamides through stereoselective 1,3-hydrogen shifts

• Ryuji Hayashi,
• John B. Feltenberger,
• Andrew G. Lohse,
• Mary C. Walton and
• Richard P. Hsung

Beilstein J. Org. Chem. 2011, 7, 410–420, doi:10.3762/bjoc.7.53

• exclusive E-selectivity, including structurally intriguing examples such as 24–28 (Table 3, entries 9–15). Moreover, a protected alcohol or amine in the allenamide did not impede the isomerization process (Table 3, entries 10–14), leading to more functionalized trienes. To continue elevating the level of

• 1,3-hydrogen shift than the neutral one. Lastly, a non-radical proton-transfer like mechanism could also be at play under conditions using protic solvents or owing to the presence of trace of amount of water (Figure 2, right). These last two models also reveal some insight into the E-selectivity given

• the pro-E configured transition state (TS) (see the R1 group). Along the same line, if the reaction proceeds through a radical pathway, the observed E-selectivity in the thermal 1,3-hydrogen shift should be favoured because the pro-Z transition state experiences a greater allylic strain compared to

Cross-metathesis of allylcarboranes with O-allylcyclodextrins

• Ivan Šnajdr,
• Zbyněk Janoušek,
• Jindřich Jindřich and
• Martin Kotora

Beilstein J. Org. Chem. 2010, 6, 1099–1105, doi:10.3762/bjoc.6.126

• 19% yields, respectively. Finally, the reactions of the cyclodextrin derivatives 2a–2c with 1c afforded the corresponding carboranylcyclodextrins 3ca, 3cb, and 3cc in 18, 19 and 20% isolated yields, respectively. It is also of note to mention here the impressive E-selectivity of the cross-metathesis

Polyionic polymers – heterogeneous media for metal nanoparticles as catalyst in Suzuki–Miyaura and Heck–Mizoroki reactions under flow conditions

• Klaas Mennecke and
• Andreas Kirschning

Beilstein J. Org. Chem. 2009, 5, No. 21, doi:10.3762/bjoc.5.21

• partners. With n-butylamine as base and 2.5 mol% catalyst 3 in DMF at 120 °C and a flow rate of 2 mL/min it was possible to achieve full conversion with complete E-selectivity within 30 min. Formation of by-products resulting from homocoupling was not observed. When 4′-iodoacetophenone (23) was exchanged