A series of enantiomerically enriched tropanes was synthesized by the rhodium(II) octanoatecatalyzed reaction of various N-BOC-protected pyrroles with vinyldiazomethanes. The overall 3 + 4 annulation occurs by a tandem cyclopropanation/Cope rearrangement. Asymmetric induction was best achieved in these transformations by using either (S)-lactate or (R)-pantolactone as a chiral auxiliary on the vinyldiazomethanes. Reactions carried out with the chiral catalyst tetrakis-[N-(4-tert-butylbenzenesulfonyl)-(L)-prolinato]dirhodium (2) provided moderate asymmetric induction, but also resulted in the formation of isomeric azabicyclooctane side products. The utility of the synthetic process was demonstrated through the asymmetric synthesis of (-)-anhydroecgonine methyl ester and (-)-ferruginine.

These data suggest that drugs with a higher affinity for the DA versus the 5-HT transporter are more likely to be self-administered.

A series of 7-azabicyclo[2.2.l]hept-5-ene complexes are prepared from [0s(NH3)5(q2-L)l2+ (L = pyrrole, 1-methylpyrrole, 2,5-dimethylpyrrole, 1,2,5-trimethylpyrrole, or 1-(trimethylsily1)pyrrole) and various dipolarophiles (e.g., acrylonitrile, methyl acrylate, a-methylene-y-butyrolactone, dimethyl maleate, dimethyl fumarate, N-phenyl maleimide, cyclopentene-1,2-dicarboxylic acid anhydride, and (E>-and (a-methyl 3-(3'-pyridyl)acrylate). The cycloaddition is promoted by coordination of the pyrrole with [Os(NH&]*+ across C3 and C4, transforming the uncoordinated portion of the pyrrole nucleus into an azomethine ylide capable of undergoing 1,3-dipolar cycloadditions.The metal serves not only to activate the pyrrole ring but also to stabilize the resulting 7-azabicyclo[2.2.l]heptene ligands. A number of organic 7-azabicyclo[2.2. llheptanes, including analogs of the alkaloid epibatidine, have been synthesized by this methodology. For the cases examined, the cycloaddition favors ex0 stereochemistry of the electronwithdrawing substituent when the pyrrole nitrogen is unsubstituted. Crystal structures have been determined for the complexes obtained from the reactions of pyrrole with N-phenylmaleimide @a), 2,5dimethylpyrrole with dimethyl maleate (13a), and 2,5-dimethylpyrrole with a-methylene-y-butyrolactone (22a).

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