A reação de Diels-Alder no início do século vinte um

Gelatin/dextran‐based hydrogel cross‐linked by Diels–Alder click chemistry: the swelling and potassium diclofenac releasing

“…In the specific case of Diels – Alder synthesis, the reaction consists of a [4 + 2] cycloaddition between a conjugated diene with four π electrons and a dienophile with two π electrons, that is, a substituted alkene. The rearrangement of π electrons results in a six‐membered cyclic adduct, whose kinetics are favoured when the dienophile source is α‐substituted by electron withdrawal groups, such as carbonyls (Brocksom et al, 2010; Gandini, 2013). In addition, hydrogen bonds and hydrophobic interactions are also involved in adduct formation, and, consequently, the Diels – Alder reaction takes place faster at mild temperature and aqueous media, reducing the cost and potential toxicity caused by solvents (Meijer et al, 1998).…”

Rhodium(i)-catalyzed asymmetric [4 + 2] cycloaddition reactions of 2-alkylenecyclobutanols with cyclic enones through C–C bond cleavage: efficient access totrans-bicyclic compounds

“… 3 Among these, the Diels–Alder (DA) reaction constitutes one of the most widely used and efficient approaches. 4 However, DA adducts generally possess cis configurations that are less common in natural products; meanwhile, asymmetric catalysis has had only limited success. 5 Therefore, new catalytic methods for the expedient synthesis of bicyclic motifs in a trans - and enantioselective fashion are highly desirable.…”

The Diels-Alder reactions of carbomethoxy-p-benzoquinones with simple dienes

“…[1][2][3] We now present our results on the Diels-Alder reactions of carbomethoxy-pbenzoquinones with simple dienes, performed at room temperature, with Lewis acid catalysis, and with microwave irradiation.…”