Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

• would afford the [2 + 2] adduct. Hydroruthenation of the allene produces 103 which can either undergo reductive elimination to afford the cyclopropanated bicyclic alkene or undergo a [2 + 2] cycloreversion to generate the Ru–carbene 104. The Ru–carbene 104 can rearrange to 100 through a 1,3-migration of

Norbornadiene-functionalized triazatriangulenium and trioxatriangulenium platforms

• Roland Löw,
• Talina Rusch,
• Tobias Moje,
• Fynn Röhricht,
• Olaf M. Magnussen and
• Rainer Herges

Beilstein J. Org. Chem. 2019, 15, 1815–1821, doi:10.3762/bjoc.15.175

• (NBD) and quadricyclanes (QC) attached to TATA and TOTA platforms which can be used to check if these accelerated rates and the spin change mechanism also apply to [2 + 2] cycloreversions (QC→NBD). Keywords: [2 + 2] cycloaddition; [2 + 2] cycloreversion; norbornadiene; photochemical isomerization

• -catalysed” [2 + 2] cycloreversion on bulk gold of quadricyclane 1b to norbornadiene 1a (Figure 1). The cycloreversion of most quadricyclane systems proceeds smoothly in solution upon irradiation in the presence of triplet sensitizers [7]. If 1b is adsorbed on a gold surface the bulk gold could take the role

Metal–ligand multiple bonds as frustrated Lewis pairs for C–H functionalization

• Matthew T. Whited

Beilstein J. Org. Chem. 2012, 8, 1554–1563, doi:10.3762/bjoc.8.177

• ) [27]. Similar reactions have been observed for nucleophilic imido complexes, in which imines can be formed by an oxo/imide metathesis at zirconium(IV). As with the Schrock neopentylidene, the reaction proceeds through a four-membered metallacycle, which eliminates the organic product through a [2 + 2

• ] cycloreversion (Scheme 4) [28]. Other early metal imides may demonstrate similar reactivity, as seen in a reaction reported by Schrock for a tantalum(V) imide [29]. The reactions described above represent only a few of the many metal–ligand cooperative reactions of nucleophilic, multiply bonded species with

Carbohydrate-auxiliary assisted preparation of enantiopure 1,2-oxazine derivatives and aminopolyols

• Marcin Jasiński,
• Dieter Lentz and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2012, 8, 662–674, doi:10.3762/bjoc.8.74

• lithiated methoxyallene to give the double adduct G. After aqueous work-up, hydroxylamine derivative H underwent a ring-closure to 1,2-oxazetidine derivative I. It is known that this class of compounds can suffer a thermally induced [2 + 2] cycloreversion involving N–O bond cleavage [39][40], which, in our