Dimerization of Aryl Sulfonates by in situ Generated Nickel(0)
摘要:
A mild and user-friendly nickel-catalyzed method for the reductive homocoupling of aromatic tosylates is presented. The reaction proceeds between room temperature and 60 degrees C, with stable substrates (ArOTs) easily prepared from inexpensive and commercially available phenols or naphthols. It relies on a catalytic amount (10 mol%) of a robust catalyst (NiBr(2)bipy) that does not require the preparation of sensitive organometallic intermediates. Yields are good to excellent.
A novel Ni0‐catalyzed carboxylation of aryl tosylates with carbon dioxide has been achieved under moderate temperatures and atmospheric pressure. In this procedure, the active Ni0 species is generated in situ by simply mixing the Ni0 precatalyst [NiBr2(bipy)] with an excess of manganese metal. This approach requires neither a glove‐box nor the tedious preparation of sophisticated intermediate organometallic
Graphite/Methanesulfonic Acid (GMA) as a New Reagent for Sulfonylation of Phenols and Thia-Fries Rearrangement of Aryl Sulfonates to Sulfonylphenols
作者:Hashem Sharghi、Zahra Shahsavari-Fard
DOI:10.1002/hlca.200490295
日期:2005.1
A new facile method for direct sulfonylation of phenols was developed. Graphite in methanesulfonicacid (GMA) was used to prepare sulfonylphenols by sulfonylation of phenol and naphthalene derivatives with p-toluenesulfonic acid (=4-methylbenzenesulfonic acid) (Table 1) and the thia-Friesrearrangement of arylsulfonates (Table 4). Mechanistic studies showed that the sulfonylation reaction of phenols
New Preparative Method of Aryl Tosylates by Using Organobismuth Reagents
作者:Naoto Sakurai、Teruaki Mukaiyama
DOI:10.1246/cl.2007.928
日期:2007.7.5
A newmethod for the preparation of aryl tosylates by using pentavalent bismuth is described. Treatment of 10-aryl-phenothiabismine 5,5-dioxides, m-chloroperoxybenzoic acid (MCPBA) and p-toluenesulfonic acid monohydrate in dichloromethane affords aryl tosylates in good to high yields.
A New Preparative Method of Aryl Sulfonate Esters by Using Cyclic Organobismuth Reagents
作者:Teruaki Mukaiyama、Naoto Sakurai
DOI:10.3987/com-07-s(w)63
日期:——
A newmethod for the preparation of aryl sulfonate esters by using a cyclic pentavalent bismuth is described. Aryl sulfonate esters are formed in good to high yields by treating 10-arylphenothiabismine 5,5-dioxides, m-chloroperoxybenzoic acid (m-CPBA) and various sulfonic acids in dichloromethane.