New high-yielding synthetic routes to the small-molecule endofullerenes H2O@C60, D2O@C60 and H2@C60 are described. The use of high temperatures and pressures for the endohedral molecule incorporation are avoided. A new partial closure step using PPh3, and final suturing using a novel Diels-Alder/retro-Diels-Alder sequence are amongst the advances reported.

Because of its thermal reversibility, the retro-Diels-Alder (RDA) reaction represents an appealing possibility to produce self-healing polymers with well-defined architectures and tunable properties [1]. However, the polymer architecture for which the Diels-Alder (DA) reaction can best be used to contribute to the healing process is still not well-defined. Therefore, new terpolymers containing ...

diels–alder [2+4] cycloaddition products of the reaction between c20 and c4h4x2 or c2o2x2 (x = h, f, cl, ch3, nh2, no2, and oh) were studied atb3lyp level of theory with 6-31g, 6-31g(d, p) and 6-311g(d, p) basis sets. the homo–lumo gaps of kohn–sham orbitals for most of the adducts show evident increase compared with the gap value of c20, suggestive of more stability in the adducts. the thermod...

[reaction: see text] A high-yielding method is described for the rapid synthesis of very hindered cyclohexenes by the Diels-Alder reaction of hindered silyloxy dienes and dienophiles using the mixed Lewis acid catalyst system (AlBr(3)/AlMe(3)). Thus, reaction of the hindered diene 4 with various substituted enones gave good yields of the expected cycloadducts even though both partners are quite...

Multicomponent reactions allow for more bond-forming events per synthetic operation, enabling more step- and time-economical conversion of simple starting materials to complex and thus value-added targets. These processes invariably require that reactivity be relayed from intermediate to intermediate over several mechanistic steps until a termination event produces the final product. Here, we r...

The time-resolved mechanisms for eight Diels-Alder reactions have been studied by quasiclassical trajectories at 298 K, with energies and derivatives computed by UB3LYP/6-31G(d). Three of these reactions were also simulated at high temperature to compare with experimental results. The reaction trajectories require 50-150 fs on average to transverse the region near the saddle point where bonding...

Synthetic access to regiodifferentiated meta-amino phenols is described. The strategy relies upon distinct deprotonation conditions to afford regioisomeric thermodynamic and kinetic dienes that undergo a tandem Diels-Alder and retro-Diels-Alder sequence with assorted acetylenic dienophiles to afford a range of aromatic products.

Two new surfactant molecules are reported that contain thermally labile Diels-Alder adducts connecting the hydrophilic and hydrophobic sections of each molecule. The two surfactants possess identical hydrophobic dodecyl tail segments but have phenol and carboxylic acid hydrophilic headgroups, respectively. Deprotonation with potassium hydroxide affords the formation of water-soluble surfactants...

The reaction of furylacrylic acid with cyclopentadiene in toluene gave the expected Diels-Alder endo-and exo-adductsin -1 : 1 ratio. The adducts were separated by iodolactonization method to provide 3-endo-(2'-furyl) bicyclo 12.2.11 hept-5-ene- 2-exo-carboxylic acid and 3-exo-(2'-fury1)bicyclo 12.2.11 hept-5-ene-2-endocarboxylic acid. Esterification of these acids by MeI / HMPA gave the exp...

An efficient synthesis of the C4-epi-lomaiviticin B core is reported. The synthesis features a diastereoselective anionic formal furan Diels-Alder reaction and a stereoselective oxidative enolate dimerization. During the investigation, subtle yet critical stereoelectronic effects imparted by the C4-stereocenter were observed.