2-alkylchromans, as well as an azachroman derivative. The asymmetric version of this approach via a Noyori-catalyzed ketone reduction and subsequent cyclization is likewise highlighted. A convergent three-step method for the synthesis of 2-substituted chromans is described. These results have been accomplished via the Heck coupling of readily accessible allylic alcohols and 2-iodophenols, followed by reduction and
A Highly Chemoselective, Zr-Catalyzed C–O Bond Functionalization of Benzofuran
作者:Shuhui Yow、Adi E. Nako、Léonard Neveu、Andrew J. P. White、Mark R. Crimmin
DOI:10.1021/om4008295
日期:2013.10.14
The chemoselective C-O bond functionalization of benzofuran with an aluminum dihydride may be catalyzed by zirconocene dichlorides. The reaction proceeds with the formal addition of a C-O bond to, and elimination of dihydrogen from, aluminum. The product of C-O bond alumination reacts with benzaldehyde via insertion of the carbonyl into the newly formed Al-C bond.
Protecting group-free use of alcohols as carbon electrophiles in atom efficient aluminium triflate-catalysed dehydrative nucleophilic displacement reactions
作者:Adam Cullen、Alfred J. Muller、D. Bradley G. Williams
DOI:10.1039/c7ra08784e
日期:——
Benzylic and allylic alcohols are rendered electrophilic without chemical modification by the use of aluminium triflate as catalyst. The reaction succeeds with alcohol, thiol, carbon and nitrogen nucleophiles. When phenols are employed as nucleophiles, C-alkylation ensues. An advanced application of the method is demonstrated in the synthesis of 2H-chromenes and their N and S analogues.
Wet SiO<sub>2</sub>As a Suitable Media for Fast and Efficient Reduction of Carbonyl Compounds with NaBH<sub>3</sub>CN under Solvent-Free and Acid-Free Conditions
作者:Mehri Kouhkan、Behzad Zeynizadeh
DOI:10.5012/bkcs.2010.31.10.2961
日期:2010.10.20
Reduction of carbonyl compounds such as aldehydes, ketones, α,β-unsaturated enals and enones, α-diketones and acyloins was carried out readily with NaBH 3 CN in the presence of wet SiO 2 as a neutral media. The reactions were performed at solvent-free conditions in oil bath (70 - 80 °C) or under microwave irradiation (240 W) to give the product alcohols in high to excellent yields. Regioselective 1,2-reduction