Efficient and chemoselective protection of aldehydes to the corresponding dimethyl acetals have been carried out by mixture of trimethyl orthoformate and methanol in the presence of a catalytic amount of TMSCl or AlCl3 under microwave irradiation. Under these conditions, acetalization of ketones does not take place and they remain intact under reaction conditions. The results are compared with ...

Chemoselective hydrogenation of unsaturated aldehyde to alcohol has attracted growing interests in recent years due its widespread applications fine chemicals. However, the C=O bond was thermodynamically and kinetically unfavorable over C=C bond. Thus, obtain from is very difficult most catalytic systems. In this work, ZnAl-hydrotalcite-supported cysteine-capped Au25 nanoclusters were used as p...

Catalytic amounts of Co(Sal(tBu,tBu))Cl and organosilane irreversibly isomerize terminal alkenes by one position. The same catalysts effect cycloisomerization of dienes and retrocycloisomerization of strained rings. Strong Lewis bases like amines and imidazoles, and labile functionalities like epoxides, are tolerated.

The stereospecific intramolecular alkylation of a hydroperoxyacetal provides the basis for the first asymmetric synthesis of the dioxane propionate core of the peroxyplakorates. Chemoselective hydrometallation of an alkyne in the presence of a peroxide is used to introduce a synthon for the polyunsaturated side chains of the peroxyplakorates. The route suggests a general solution for the 1,2-di...

Bulky aluminum Lewis acids such as MAD and MABR are introduced as new efficient catalysts in substoichiometric amounts for the allylation of aldehydes with allyltributylstannane. In addition, chemoselective allylation of a less hindered or aromatic aldehyde was achieved with catalytic amounts of the carbonyl receptor aluminum tris(2,6-diphenyl-phenoxide) (ATPH).