Norbornadiene Explained

Norbornadiene is an organic compound and a bicyclic hydrocarbon. Norbornadiene is of interest as a metal-binding ligand, whose complexes are useful for homogeneous catalysis. It has been intensively studied owing to its high reactivity and distinctive structural property of being a diene that cannot isomerize (isomers would be anti-Bredt alkenes). Norbornadiene is also a useful dienophile in Diels-Alder reactions.

Synthesis

Norbornadiene can be formed by a Diels-Alder reaction between cyclopentadiene and acetylene^[1]

Reactions

Quadricyclane, a valence isomer, can be obtained from norbornadiene by a photochemical reaction when assisted by a sensitizer such as acetophenone:

The norbornadiene-quadricyclane couple is of potential interest for solar energy storage when controlled release of the strain energy stored in quadricyclane back to norbornadiene is made possible.^[2]

Norbornadiene is reactive in cycloaddition reactions. Norbornadiene is also the starting material for the synthesis of diamantane^[3] and sumanene and it is used as an acetylene transfer agent for instance in reaction with 3,6-di-2-pyridyl-1,2,4,5-tetrazine.^[4]

As a ligand

Norbornadiene is a versatile ligand in organometallic chemistry, where it serves as a two-electron or four-electron donor. (Norbornadiene)molybdenum tetracarbonyl is used as a source of "Mo(CO)₄", exploiting the lability of the diene ligand in this case.^[5] which is a useful source of "chromium tetracarbonyl," e.g. in reactions with phosphine ligands.

The norbornadiene analogue of cyclooctadiene rhodium chloride dimer has been used in homogeneous catalysis. Chiral, C₂-symmetric dienes derived from norbornadiene have also been described.^{[6] [7]}

See also

• Norbornane a saturated compound with the same carbon skeleton.
• Norbornene a compound with the same carbon skeleton, but with one less double bond.

References

1. Orrego‐Hernández . Jessica . Hölzel . Helen . Quant . Maria . Wang . Zhihang . Moth‐Poulsen . Kasper . 2021-10-14 . Scalable Synthesis of Norbornadienes via in situ Cracking of Dicyclopentadiene Using Continuous Flow Chemistry . European Journal of Organic Chemistry . en . 2021 . 38 . 5337–5342 . 10.1002/ejoc.202100795 . 1434-193X.
2. Rh(III)-Photosensitized Interconversion of Norbornadiene and Quadricyclane . Gregory W. Sluggett . Nicholas J. Turro . Heinz D. Roth . amp . . 1997 . 101 . 8834–8838 . 10.1021/jp972007h . 47. 1997JPCA..101.8834S . 10.1.1.130.1791.
3. Diamantane in Organic Syntheses Coll. Vol. 6, p.378; Vol. 53, p.30 Online Article
4. π-Bond Screening in Benzonorbornadienes: The Role of 7-Substituents in Governing the Facial Selectivity for the Diels-Alder Reaction of Benzonorbornadienes with 3,6-Di(2-pyridyl)-s-Tetrazine . Ronald N. Warrener . Peter A. Harrison . amp . . 2001 . 6 . 353–369 . 6236418. 10.3390/60400353 . 4. 53874105 . free.
5. High yield synthesis and structures of some achiral and chiral (diphosphine)tetracarbonylchromium(0) chelate complexes with tetracarbonyl(norbornadiene)chromium(0) as complexation reagent . Markus Strotmann . Rudolf Wartchow . Holger Butenschön . amp . . KK–1112F . 2004 .
6. Ryo Shintani, Tamio Hayashi "Chiral Diene Ligands for Asymmetric Catalysis" Aldrich Chimica Acta 2009, vol. 42, number 2, pp. 31-38.
7. 10.1021/acs.chemrev.2c00218. Chiral Diene Ligands in Asymmetric Catalysis . 2022 . Huang . Yinhua . Hayashi . Tamio . Chemical Reviews . 122 . 18 . 14346–14404 . 35972018 .