The regioselective installation of chalcogen atoms into biaryl scaffolds is an important synthetic task due to the great value of chalcogen-containing biaryl derivatives in many fields. Here we undertake this task by developing a regioselective2,2′-dichalcogenation of 2-bromobiaryls with common chalcogen sources using an organolanthanum-mediated one-pot, two-step protocol. This strategy features high
Synthesis and Properties of Novel Medium-sized Heterocyclic Compounds Containing Two Sulfur Atoms in the Ring and Synthetic Approaches to Conjugated Cyclic Disulfonium Ylides
作者:Hiroshi Shimizu、Hiroyoshi Watanabe、Masahiro Mizuno、Tadashi Kataoka、Mikio Hori
DOI:10.3987/com-99-s(i)5
日期:——
Tribenzo[b,f,h][1,4]dithiecin (8) was prepared by coupling 2,2'-bis(bromomethyl)biphenyl (10) with 1,2-benzenedithiol (11) in the presence of NaH in acetonitrile. Another novel dithiecin derivative, 1,8-dihydro-2,7-benzodithiecin (9) was synthesized by coupling of 1,4-dimercapto-2,3-O-isopropylidene-Lg-threitol (13a) with alpha,alpha'-dibromo-o-xylene (12), followed by hydrolysis and subsequent dehydration via the mesylate derivative (16). The benzodithiecin (9) was also prepared by treatment of dithiol (18) with butadiyne along with alpha,alpha'-bis(1-buten-3-ynylthio)-o-xylene (19) as a byproduct. Compound (19) was subjected to an intramolecular coupling reaction using CuCl-pyridine-O-2 in benzene to yield the 12-membered ring compound (23). We also describe our effort to prepare the corresponding cyclic diylide compounds from the above new dithiecins (8) and (9), and known dithiecin (7).
Synthesis and reactivity of 2-(ethylthio) phenylcopper: A stable organocopper compound carrying an intramolecular sulfane ligand
作者:Shinji Toyota、Michinori Ōki
DOI:10.1016/s0022-328x(96)06496-0
日期:1997.4
An unusually stable organocopper compound carrying an intramolecular sulfane ligand, 2-(ethylthio)phenylcopper, was synthesized via the reaction of the corresponding organolithium with a copper(I) halide (CuX). This compound was obtained in two forms: one is a salt - free compound which is insoluble in ordinary solvents, the other is a soluble complex of [2-(ethylthio)phenylcopper](2) . CuX composition. These compounds were either hydrolyzed or underwent a coupling reaction to produce a biphenyl when heated. While these organocoppers are less reactive towards various electrophiles than other known arylcoppers, the soluble complex gives ketones with acyl halides in low yields. The properties as well as the reactivities of the stable organocopper compounds are reported.