By using solvent-free and heat conditions, the Petasis boronic Mannich reaction of salicylaldehydes with various boronic acids and secondary amines without catalyst is described. The alkylaminophenols were obtained in moderate to good yields in a shorter reaction time than the traditional methods.

No abstract

A series of 14-{[(Un)substituted phenyl] or alkyl}-14H-dibenzo[a,j]xanthenes were prepared under solvent-free conditions by Yb(OTf) 3 catalyzed condensation reactions of β-naphthol with various aldehydes. The process presented here is operationally simple, environmentally benign and has good to excellent yields. Furthermore, the catalyst can be recovered conveniently and reused efficiently.

Xanthene derivatives R 0360 Synthesis of 14-{[(Un)substituted phenyl] or alkyl}-14-H-dibenzo[a,j]xanthenes Using Yb(OTf) 3 as an Efficient Catalyst under Solvent-FreeConditions. -Conventional Lewis acids show a poor effect on the yield of the product while the rare-earth catalyst greatly enhances the yields of dibenzoxanthenes (III). Both electron-rich and electron-deficient benzaldehydes work well, affording high yields of (III). Aliphatic aldehydes (Ia) and (Ib) afford lower yields, even after a longer reaction time. The environmentally benign catalyst can be recovered conveniently and reused efficiently. -(WANG*, L.-M.; SUI, Y.-Y.; ZHANG, L.; Chin.

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