- Copper-Catalyzed Oxidative Acetalization of Boronic Esters: An Umpolung Strategy for Cyclic Acetal Synthesis
-
A protocol for the acetalization of boronic esters is described. The reaction is catalyzed by copper, and the conditions proved to be mild and were amenable to a variety of functional groups. We expanded the Chan-Lam coupling to include C(sp3) nucleophiles and converted them into corresponding acetals. This method allows for the orthogonal acetalization of substrates with reactive, acid-sensitive functional groups.
- Miller, Eric M.,Walczak, MacIej A.
-
-
Read Online
- Reactivity of Isocoumarins. II. Reaction of 1-Ethoxyisochroman with nucleophilic reagents
-
The C(1)-position of 1-ethoxyisochroman (3) is very susceptible to attack by various nucleophilic reagents.Reaction of 3 with various alcohols, such as benzyl alcohols, N,N-dimethylaminoethanol and ethyl lactate, gave corresponding 1-alkoxyisochromans (5,7,8 and 9).Reaction of 3 with phenols, such as phenol and methyl p-hydroxybenzoate, gave 1-(hydroxyphenyl)isochromans (11, 12, 13 and 16).Some monoalkoxybenzenes were unreactive with 3 but 1,3-dimethoxybenzene gave corresponding 1-(dimethoxyphenyl)isochromans (14 and 15).Reaction of 3 with an emanine such as 1-morpholino-1-cyclohexene gave 2-(1-isochromanyl)-1-(4-morpholino)cyclohexene, which was hydrolyzed to give 2-(1-isochromanyl)cyclohexanone (17).Reaction of 3 with ketones, i.e., cyclohexanone and ethyl acetoacetate, gave 17 and ethyl α-(1-isochromanyl)acetoacetate (18), respectively.
- Yamato, Masatoshi,Ishikawa, Tadataka,Kobayashi, Toshio
-
p. 2967 - 2971
(2007/10/02)
-