Cyclopentene diamination

Some alicyclic 1,2-diamine derivatives have recently been shown to have interesting CNS properties. For example, eclanamine (34) is an antidepressant with a rapid onset of action. The reasons for its potency are not as yet clear but pharmacologists note that the drug desensitizes adrenergic alpha-2 receptors and antagonizes the actions of clonidine. The synthesis of eclanamine starts with attack of cyclopentene oxide (30) by dimethylamine (to give 31). This product is converted to the mesylate by reaction with sodium hydride followed by mesyl chloride. Attack of... 

Andersson et al. further improved their diamine catalyst 62 by introduction of substituents on the pyrrolidine ring [63], Of various catalysts tested, the dimethy-lated compound 63 proved best (Scheme 13.32) [63], As summarized in Scheme 13.32, excellent enantiomeric excesses were achieved by use of catalyst loadings as low as 5 mol%, and even for notoriously difficult substrates such as cyclopentene epoxide. 

There is one direct method of preparing primary diamines from alkoies, in which the alkene is treated with nitric oxide and a cobalt complex, and the intermediate worked up reductively. The two-stage reduction gives better stereoselectivity (Scheme 38). Typical yields from alkenes listed and cisurans se-lectivities (expected product first) are cyclopentene, 70%, 70 30 rr[Pg.484]

Synthesis of optically active PF-04634817 (271) based on commercially available (-)-Vince Lactam as chirality source. Starting from (-)-Vince Lactam the chiral key 4-amino-2-cyclopentene-l-carboxylic acid derivative 286 was synthesized. The componnd 286 is dimethyl pyrrole protected form of corresponding aminoacid, which was subjected to amide coupling with Boc-protected diamine 287 to give... 

The synthetic route to the structurally related bis-thioureas of type 32 from (R)-5,5, 6,6, 7,7, 8,8 -octahydro-l,T-binaphthyl-2,2 -diamine was reported by Shi. The effectiveness of the acid-base synergistic catalysis of parent 32a and N,N-diisopropylethylamine was verified by application to the asymmetric Henry reaction of nitromethane with aromatic aldehydes (Scheme 7.57) [86]. Moreover, the Morita-Bayhs-Hillman reaction between 2-cyclohexen-l-one or 2-cyclopenten-1-one and aromatic aldehydes was found to proceed with moderate to good levels of enantioselectivity under the catalysis of 32b, which has additional 3,5-bis(trifluoromethyl)phenyl groups at the 3,3 -positions of the octahydrobinaph-thyl backbone, and l,4-diazabicyclo[2.2.2]octane (DABCO) (Scheme 7.57) [87]. 

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