The direct reduction of alcohols using chlorodiphenylsilane as a hydride source in the presence of a catalytic amount of indium trichloride is described. Benzylic alcohols, secondary alcohols, and tertiary alcohols were effectively reduced to give the corresponding alkanes in high yields. A compound bearing both primary and secondary hydroxyl groups was reduced only at the secondary site to afford the primary alcohol after workup with Bu(4)NF. This system showed high chemoselectivity only for the hydroxyl group while not reducing other functional groups that are readily reduced by standard reducing systems. Thus alcohols bearing ester, chloro, bromo, or nitro groups, which are sensitive to LiAlH(4) or Zn/H(+), were selectively reduced only at the hydroxyl sites by the chlorodiphenylsilane/InCl(3) system. NMR studies revealed the reaction course. The hydrodiphenylsilyl ether is initially formed and then, with InCl(3) acting as a Lewis acid, forms an oxonium complex, which accelerates the desiloxylation with donation of the hydrogen to the carbon.

To construct CÀC bonds, coupling reactions between reactive nucleophiles such as organometallic compounds (R'M) and halides or a related species (RX) are undoubtedly a useful process. The species RX and R'M are often prepared from alcohols (ROH) and active methylenes (R'H), respectively. However, the coupling reaction intrinsically produces a salt (MX) alongside the desired product (RÀR'). The direct[*] Dr.

The indium hydride generated from NaBH4 and InCl3, is a promising candidate of alternative to Bu3SnH. In particular, the catalytic performance of InCl3 in the dehalogenation of alkyl and aryl halides, intramolecular cyclization and intermolecular coupling reaction are noteworthy.

We successfully observed the phenomenon of “nonequilibrium local heating” occurring to the DMSO molecules in proximity of the Co particles under microwave irradiation by real-time in situ Raman spectroscopy. This phenomenon was induced only under microwave irradiation but not by conventional heating. This nonequilibrium local heating can be realized by the input of the power more rapid than that of the heat loss induced by the temperature difference between the heated microdomains and the surrounding domains. We have demonstrated the enhancement in the dehalogenation reaction of the C(sp3)−Cl bond of 2-chloroethylbenzene and 4-phenylbutyl chloride caused by the “nonequilibrium local heating” of the surface of the Co and/or Fe particles under microwave irradiation.