The Diels-Alder reaction is a [4+2] cycloaddition (4 pi electrons from the diene and 2 pi electrons from the dienophile) that yields a functionalized 6-membered ring product. During the Diels-Alder reaction, two pi-bonds are converted to two sigma-bonds.

In organic chemistry, a cycloaddition is a chemical reaction in which "two or more unsaturated molecules (or parts of the same molecule) combine with the formation of a cyclic adduct in which there is a net reduction of the bond multiplicity ". The resulting reaction is a cyclization reaction.

The Diels-Alder reaction is a [4+2] cycloaddition (4 pi electrons from one reactant and 2 pi electrons from the other reactant) that yields a functionalized 6-membered ring product. It is the most useful cycloaddition reaction due to the ubiquity of 6-membered rings and its ability to reliably control stereochemistry in the product.

2024年7月30日 · A cycloaddition reaction is one in which two unsaturated molecules add to one another to yield a cyclic product. As with electrocyclic reactions, cycloadditions are governed by the orbital symmetry of the reactants.

Cycloaddition reactions involve the formation of a cyclic product due to addition of two different π bond containing components, which are joined by newly formed two σ bonds at their ends at the expense of two π bonds.

2024年4月22日 · Cycloaddition reactions (there are also 4+4, etc.) have some very interesting characteristics. The first is that experimentally it is observed that 2+2 or 4+4 reactions hardly occur in the fundamental state, i.e. thermally. Whereas the Diels-Alder type reactions (which are 2+4) occur very easily.

A cycloaddition reaction is one in which two unsaturated molecules add to one another to yield a cyclic product. As with electrocyclic reactions, cycloadditions are governed by the orbital symmetry of the reactants.

The Diels-Alder Reaction (DAR), reported in 1928 by Otto Diels and Kurt Alder, is a thermal, concerted, suprafacial, [4+2] cycloaddition. The prototypical DAR is illustrated in Fig. 6. While 1,3-butadiene is a viable diene in the reaction, ethylene itself is a poor dienophile (dienophobe?).

Cycloadditions are reactions that form new loops within a molecule by taking pi bonds and creating new sigma bonds. Even though there are many types of such reactions, they are classifiable by the size the reactants and the products.

2014年2月24日 · In this notation the reaction (a) and (b) of the preceding paragraph would both be described as [2+4] cycloadditions, and (c) as a [2+2+2] cycloaddition. The symbol a or s (a = ) is often added (usually as a subscript after the number to designate the stereochemistry of addition to each fragment.