Caryolene-forming carbocation rearrangements

• Quynh Nhu N. Nguyen and
• Dean J. Tantillo

Beilstein J. Org. Chem. 2013, 9, 323–331, doi:10.3762/bjoc.9.37

• positioned on opposite sides of the hydrocarbon substrate due to the steric congestion at its core (note the position of NH3 throughout Figure 7), a scenario that could be probed by deuterium labeling of farnesyl diphosphate if a suitable caryolene synthase were isolated. The energetics for both pathways

Radical zinc-atom-transfer-based carbozincation of haloalkynes with dialkylzincs

• Fabrice Chemla,
• Florian Dulong,
• Franck Ferreira and
• Alejandro Pérez-Luna

Beilstein J. Org. Chem. 2013, 9, 236–245, doi:10.3762/bjoc.9.28

• warming, the zinc carbenoid is stereochemically labile and isomerizes to its more stable form. In the absence of added air, no decomposition of the carbenoid intermediate is observed at room temperature for at least 24 h. Deuterium labeling and iodolysis experiments evidence that the zinc carbenoids

Recent advances in the gold-catalyzed additions to C–C multiple bonds

• He Huang,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103

• sp3-hybridized C–H bond can be achieved by undergoing 1,3-addition to a vinyl–carbenoid intermediate [142]. The bicyclo[3.2.1]oct-6-en-2-ones 265 and 267 could be synthesized stereoselectively by this method. Deuterium labeling experiments indicated the cyclization involved an unprecedented 1,3

• via oxidative gold catalysis and provided expedient access to various substituted N- or O-heterocycles (344–351) (Scheme 57). Deuterium labeling experiments were carried out to unveil the reaction mechanism. The results established the anti nature of the alkene functionalization and the indispensable

Gold-catalyzed heterocyclizations in alkynyl- and allenyl-β-lactams

• Benito Alcaide and
• Pedro Almendros

Beilstein J. Org. Chem. 2011, 7, 622–630, doi:10.3762/bjoc.7.73

• reveal, 5-exo oxyauration via 16 is restricted by the steric hindrance between the (methoxymethyl)oxy group and the substituents at the quaternary stereocenter. With the aim of trapping the organo–gold intermediate to confirm the mechanism of this reaction, deuterium labeling studies with deuterium oxide

Construction of cyclic enones via gold-catalyzed oxygen transfer reactions

• Leping Liu,
• Bo Xu and
• Gerald B. Hammond

Beilstein J. Org. Chem. 2011, 7, 606–614, doi:10.3762/bjoc.7.71

• cyclization of internal diynes. Proposed solvolysis/cyclization mechanism. Gold-catalyzed cyclization of alkynyl epoxides and the 18O isotopic labeling experiment. Proposed oxygen transfer mechanism. Gold or silver-catalyzed cyclization of alkynyl epoxides and the corresponding deuterium labeling experiment.