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Cycloadditions on diamond (100) 2 x 1: observation of lowered electron affinity due to hydrocarbon adsorption

Ti Ouyang1, Xingyu Gao, Dongchen Qi

  • 1Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543.

The Journal of Physical Chemistry. B
|March 17, 2006
PubMed

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Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.
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The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
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