Bromination of endo-7-norbornene derivatives revisited: failure of a computational NMR method in elucidating the configuration of an organic structure

• Demet Demirci Gültekin,
• Arif Daştan,
• Yavuz Taşkesenligil,
• Cavit Kazaz,
• Yunus Zorlu and
• Metin Balci

Beilstein J. Org. Chem. 2023, 19, 764–770, doi:10.3762/bjoc.19.56

• atoms were determined by measuring the couplings between the relevant protons. Proton–proton couplings beyond the three bonds are observed frequently in some strained bicyclic compounds. The long-range coupling exists in a zigzag arrangement (Figure 2). In the case of norbornane if the bonding

• configuration of the substituents attached to the norbornane skeleton. Inspection of both structures 6 and 7 shows that in the case of our structure 6 a long range-coupling should be observed between the protons H2 and H6exo. However, in the case of the structure 7 proposed by the authors, a long-range coupling

• may need to re-examine his/her computational approach and try to use it rather in a supportive role in organic chemistry. Structure 6 (our assignment) and structure 7 revised by Novitskiy and Kutateladze. W or M orientaition in norbornane and the corresponding coupling constants. The determined

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

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

Diels–Alder reaction of β-fluoro-β-nitrostyrenes with cyclic dienes

• Savva A. Ponomarev,
• Roman V. Larkovich,
• Alexander S. Aldoshin,
• Andrey A. Tabolin,
• Sema L. Ioffe,
• Jonathan Groß,
• Till Opatz and
• Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2021, 17, 283–292, doi:10.3762/bjoc.17.27

• ratios similar to those of the starting mixture 2. We believe that this is a result of an exo-epoxidation which is preferred in norbornene systems [78][79]. Such a functionalization is very attractive to produce new reactive building blocks bearing the norbornane scaffold. This approach can pave a

The synthesis of functionalized bridged polycycles via C–H bond insertion

• Jiun-Le Shih,
• Po-An Chen and
• Jeremy A. May

Beilstein J. Org. Chem. 2016, 12, 985–999, doi:10.3762/bjoc.12.97

• diazopropanone-substituted norbornane 55 saw insertion into the bridgehead C–H methine to generate the cyclopentanone-fused norbornane 56. However, the shorter tether in diazoethanone-substituted 57 would form a cyclobutanone-fused product if bridgehead insertion occurred, and so insertion into a methyl C–H bond

• was preferred to give a different cyclopentanone-fused norbornane, 58. This latter intermediate was used in the total syntheses of (+)-albene and (−)-β-santalene. Srikrishna found that caged polycycles could be similarly formed via a transannular insertion [71][72][73][74][75]. His group synthesized

Superoxide chemistry revisited: synthesis of tetrachloro-substituted methylenenortricyclenes

• Basavaraj M. Budanur and
• Faiz Ahmed Khan

Beilstein J. Org. Chem. 2014, 10, 2531–2538, doi:10.3762/bjoc.10.264

• reactions of parent nortricyclenes [49] proceed through initial formation of chloroacetylated norbornane which was rapidly dehydrohalogenated upon storage at rt to give 1-acetylnortricyclene. We have applied the standard acylation reaction conditions (AlCl3, R1COCl, 1:1) to 3-methylenenortricyclenes to

Enantioselective synthesis of tricyclic amino acid derivatives based on a rigid 4-azatricyclo[5.2.1.0^2,6]decane skeleton

• Matthias Breuning,
• Tobias Häuser,
• Christian Mehler,
• Christian Däschlein,
• Carsten Strohmann,
• Andreas Oechsner and
• Holger Braunschweig

Beilstein J. Org. Chem. 2009, 5, No. 81, doi:10.3762/bjoc.5.81

• Institut für Anorganische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany 10.3762/bjoc.5.81 Abstract An enantioselective route to four tricyclic amino acids and N-tosylamides, composed of a central norbornane framework with a 2-endo,3-endo-annelated pyrrolidine ring and a 5-endo-C1 or

• β-turn-inducing building blocks in peptidomimetics and for chiral auxiliaries in asymmetric organocatalysis. Keywords: amino acid; enantioselective synthesis; norbornane; polycyclic compounds; pyrrolidine; Introduction Unnatural amino acids with a rigid bowl-shaped backbone have received

• reactions. Our studies targeted the chiral, tricyclic amino acid derivatives 7 and 8 (Figure 2), which possess a central norbornane framework equipped with a 2-endo,3-endo-annelated pyrrolidine ring. Due to the constrained, bowl-shaped backbone, these compounds may possess high potential as β-turn-inducing