Synthesis, structural reassignment, and biological activity of type B MAO inhibitors based on the 5H-indeno[1,2-c]pyridazin-5-one core.

The synthesis and enzyme inhibitor properties of reversible type B monoamine oxidase inhibitors are described. These compounds belong to the 5H-indeno[1,2-c]pyridazine family and possess a hydrophobic benzyloxy or 4,4,4-trifluorobutoxy side chain which, in contrast to a previous assignment, has been unambiguously located at C(8) of the heterocyclic moiety. Investigation of the regioisomeric structures establishes that substitution of the 5H-indeno[1,2-c]pyridazin-5-one core at C(7) vs C(8) dramatically influences the MAO-inhibiting properties of these compounds.

Synthesis of primary-alkyl selenols and selenides from primary-alkyl thiols involving diphenyl sulfonium salts.

Hexyl thiol has been transformed to hexyl selenol and related selenides and selenocyanate by substitution of the corresponding hexyldiphenylsulfonium tetrafluoroborate with selenium nucleophiles.

Metal-Mediated, Completely Diastereofacial Conjugate Addition of Trialkylstannylmetal Reagents to γ-Alkoxy-α,ß-Unsaturated Esters.

Complete control of the face of attack in the addition of stannylmetal reagents to γ-alkoxy-α,ß-unsaturated esters can be achieved by using the appropriate counterion (see scheme). The stereochemistry of addition does not depend on the configuration of the C-C double bond, although the stereoselectivity is consistently better with the Z stereoisomer, for which 100 % Si attack is obtained with Li as counterion and 100 % Re attack with LiZnEt2.