柳澤 章

The methods of asymmetric α-hydroxylation of carbonyl compounds and their equivalents, affording optically active α-hydroxy carbonyl compounds, are described here. First, enantioselective α-hydroxylation of preformed metal enolates and silyl enol ethers with a stoichiometric amount of chiral oxaziridines is presented. Second, catalytic enantioselective α-hydroxylation of preformed metal enolates, silyl enol ethers, alkenyl ethers, and enamines including nitroso aldol reaction is described. This section also covers synthesis of nonracemic α-hydroxy carbonyl compounds and α-aminooxy carbonyl compounds directly from carbonyl compounds using organocatalysts such as chiral α-amino acids. © 2012 Elsevier Ltd. All rights reserved.

The demand for functionalized aromatic compounds is growing rapidly in many research fields. Therefore, the efficient synthesis of desired aromatic compounds is a critical issue in organic synthesis. In this account, we describe new synthetic approaches to versatile aromatic compounds, such as phenols, benzenes, 3-hydroxypyridines, and styrenes, by ring-closing olefin metathesis (RCM)/aromatization and ring-closing enyne metathesis (RCEM)/aromatization of acyclic precursors. The advantages in terms of simplicity, flexibility, and avoidance of the formation of regioisomers are proof of the versatility of this method for the synthesis of aromatic compounds.