Catalytic production of pyridines from alkynes and nitriles
AssigneeStudiengesellschaft Kohle mbH
InventorsHelmut Bonnemann, Hartmut Schenkluhn
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Abstract
In the production of pyridines by the reaction of alkynes and nitriles in the presence of a cobalt-containing catalyst, special catalysts have been found to give high yields. The catalyst can be a cobalt-(I) complex compound of the type cyclooctenyl-cobalt(I)-cyclooctadiene, methyl heptadienyl-cobalt(I)-butadiene and cyclopentadienyl-cobalt(I)-cyclooctadiene, or it can be formed in situ by reducing a di- or tri-valent cobalt salt with zinc, cadmium, a metal of the main groups I to III of the Periodic Table or with an organometallic compound of any of the foregoing.
Claims7
In the cocyclization of an alkyne selected from the group consisting of acetylene, lower alkyl acetylene, phenyl-acetylene, lower alkoxy-acetylene and lower alkoxy-lower alkyl-acetylene and a nitrile selected from the group consisting of lower alkyl nitrile, phenyl nitrile, phenyl-lower alkyl nitrile and lower alkenyl nitrile in the presence of a cobalt complex compound as catalyst to form a pyridine ring compound, the improvement which comprises employing as said catalyst a member selected from the group consisting of
- a. a catalyst obtained by reducing a divalent or trivalent cobalt salt in the presence of at least one of the alkyne or nitrile reactants, employing as the reducing agent a metal or organometallic compound wherein the metal is zinc, cadmium or a metal of the main Groups I to III of the Periodic Table of elements, or
- b. a cobalt-(I) diene complex of the type cyclooctenyl-cobalt(I)-cyclooctadiene, methyl heptadienyl-cobalt(I)-butadiene and cyclopentadienyl-cobalt(I)-cyclooctadiene.
Dependencies are inferred from the claim text.