HETEROCYCLES
An International Journal for Reviews and Communications in Heterocyclic ChemistryWeb Edition ISSN: 1881-0942
Published online by The Japan Institute of Heterocyclic Chemistry
Special Issue
Ei-ichi Negishi's Special Issues,Vol. 86, No. 1, 2012
Published online: 8th August, 2012
■ Direct Asymmetric α-Allylation of Ketones with Allylic Alcohols via Pd/Enamine Cooperative Function
Shigeo Yasuda, Naoya Kumagai,* and Masakatsu Shibasaki*
*Institute of Microbial Chemistry, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141-0021, Japan
Abstract
Direct asymmetric α-allylation of ketones with allylic alcohols is described. The combination of palladium with a new phosphine ligand bearing a chiral proline moiety promoted the reaction to afford the corresponding α-allylated ketones in moderate yield and enantioselectivity.
Published online: 6th July, 2012
■ PALLADIUM-CATALYZED INTRAMOLECULAR HYDROARYLATION OF 6-BENZOFURANYL ALKYNOATES
Tsugio Kitamura* and Kensuke Otsubo
*Department of Applied Chemistry, Faculty of Science and Engineering, Saga University, Honjo-machi 1, Saga 840-8502, Japan
Abstract
Intramolecular hydroarylation of 6-benzofuranyl alkynoates efficiently proceeded using Pd(OAc)2 as catalyst in TFA and CH2Cl2 at room temperature. This intramolecular hydroarylation gave a mixture of regioisomers of furocoumarins, i.e., psoralens and allopsorallens.
Published online: 17th July, 2012
■ HYPERVALENT IODINE INDUCED OXIDATIVE CROSS COUPLING VIA Thiophene CATION RADICAL INTERMEDIATE
Toshifumi Dohi, Motoki Ito, Sho Sekiguchi, Yohei Ishikado, and Yasuyuki Kita*
*College of Pharmaceutical Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577, Japan
Abstract
The hypervalent iodine-induced arene cross coupling via a single- electron-transfer (SET) oxidation process could proceed in some extent even in heteroaromatic compounds, that is, several types thiophenes 1, using alkyl benzenes 2 as coupling partners. The structure of the obtainable heteroaromatic biaryl products could be elaborated by utilizing the known metal-catalyzed coupling technology, i.e., Negishi cross coupling, for the synthesis of multiple arylated (bi)thiophenes.
Published online: 13th August, 2012
■ Synthesis of 2-Arylbenzimidazoles in Microfluidic Chip Reactor
Ming Lei,* Wei Li, Ruijun Hu, Wan Tian, Yanguang Wang, and Hong Zhang*
*Department of Chemistry, Zhejiang University , 38 Zheda Road, Hangzhou, 310027, China
Abstract
A simple and efficient continuous flow synthesis of 2-arylbenzimidazoles from phenylenediamines and aromatic aldehydes in the presence of iodobenzene diacetate (IBD) has been developed by using a microfluidic chip reactor system. Various substituted 2-arylbenzimidazoles were obtained in high yields within 3 min under mild conditions. Compared with the classical batch systems, the present smooth procedure afforded highly selective due to the enhanced thermal and mass transfer.
Published online: 6th August, 2012
■ SYNTHESIS OF NEO-tANSHINLACTONE VIA THE PALLADIUM-MEDIATED INTRAMOLECULAR BIARYL COUPLING REACTION
Hitoshi Abe,* Toshitaka Kawai, Yoshinori Komatsu, Mayu Kamimura, Yasuo Takeuchi, and Yoshikazu Horino
*Department of Environmental Applied Chemistry, Faculty of Engineering, Toyama University, Gofuku 3190, Toyama 930-8555, Japan
Abstract
Neo-tanshinlactone (1) was synthesized by the intramolecular aryl-aryl coupling reaction of the precursor ester, which was prepared from the corresponding furan carboxylic acid (13) and naphthol (3), using a palladium reagent.