168697-62-9Relevant articles and documents
Direct preparation of benzylic manganese reagents from benzyl halides, sulfonates, and phosphates and their reactions: Applications in organic synthesis
Suh, YoungSung,Lee, Jun-Sik,Kim, Seoung-Hoi,Rieke, Reuben D.
, p. 20 - 36 (2007/10/03)
The use of highly active manganese (Mn)*, prepared by the Rieke method, was investigated for the direct preparation of benzylic manganese reagents. The oxidative addition of the highly active manganese to benzylic halides was easily completed under mild conditions. Moreover, benzylic manganese sulfonates and phosphates were prepared by direct oxidative addition of Mn* to the carbon-oxygen bonds of benzylic sulfonates and phosphates. The resulting benzylic manganese reagents were found to undergo cross-coupling reactions with a variety of electrophiles. Most of these reactions were carried out in the absence of any transition metal catalyst under mild conditions. In addition, the use of highly active manganese was also studied for preparation of homo-coupled products of functionalized benzyl halides without transition metal catalysts. These useful approaches provided not only a facile synthetic route to the preparation of resoricinolic lipids but a facile synthesis of functionalized 4-benzylpyridines by regioselective and chemo selective γ-addition of benzylic group to N-alkoxycarbonylpyridinum salts.
Simple synthesis of 5-substituted resorcinols: A revisited family of interesting bioactive molecules
Alonso, Emma,Ramon, Diego J.,Yus, Miguel
, p. 417 - 421 (2007/10/03)
The reaction of 3,5-dimethoxybenzyl trimethylsilyl ether (3) with different aldehydes (n-PrCHO, n-C11H23CHO, MeCHO, PhCHO) in the presence of lithium powder and a catalytic amount of naphthalene (4 mol %) gave, after hydrolysis, the expected alcohols 4 in moderate yields. The dehydroxylation of these compounds through the corresponding mesylates 5 or directly from benzylic derivatives by catalytic hydrogenation, afforded compounds 6, which are finally demethylated to yield 5-alkyl-3,5-dihydroxyresorcinols, such as olivetol (7a), grevillol (7b), 1,3-dihydroxy-5-propylbenzene (7c), or dihydropinosilvine (7d). Dehydration of alcohol derivatives 4 followed by demethylation led to hydroxylated stilbene-type structures, such as pinosilvine (9d), resveratrol (9e), or piceatannol (9f), which in some cases can be hydrogenated to give saturated molecules such as combretastanin B-4 tetramethyl ether (6f) or chrysotobibenzyl (6g). Finally, when the naphthalene-catalyzed lithiation of compound 3 was performed in the presence of other electrophiles [Me3SiCl, t-BuCHO, CH3(CH2)4CHO, 4-Me3SiOC6H4CHO, (CH2)5CO, PhN = C = O, PhN = CHPh], the expected reaction products 12 were isolated, after hydrolysis.
