ChemInform Abstract: A Short Synthesis of Pyridines from Deprotonated α-Aminonitriles by an Alkylation/RCM Sequence.

ChemInform Abstract: 3,4-Dihydro-2H-pyrrole-2-carbonitriles: Useful Intermediates in the Synthesis of Fused Pyrroles and 2,2′-Bipyrroles.

Various heterocyclic structures containing the pyrrole moiety have been synthesized from easily accessible 3,4-dihydro-2H-pyrrole-2-carbonitriles in one-pot procedures. 5,6,7,8-Tetrahydroindolizines, 2,3-dihydro-1H-pyrrolizines as well as 6,7,8,9-tetrahydro-5H-pyrrolo[1,2-a]azepines were obtained from these precursors in high yields in an alkylation/annulation sequence. The same conditions were applied in the synthesis of a 5,8-dihydroindolizine, which could easily be transformed to the corresponding indolizine by dehydrogenation. Furthermore, oxidative couplings of 3,4-dihydro-2H-pyrrole-2-carbonitriles with copper(II)-salts furnished 2,2′-bipyrroles as well as 5,5′-bis(5-cyano-1-pyrroline…

A short synthesis of pyridines from deprotonated α-aminonitriles by an alkylation/RCM sequence

Abstract α-Aminonitriles can serve as versatile key precursors for the synthesis of nitrogen containing heterocycles. After unsuccessful trials involving the [1,2]-Stevens rearrangement of nitrile-stabilized ammonium ylides, we herein report a simple three-step synthesis of substituted pyridines based on an alkylation/ring-closing metathesis/aromatization sequence.

3,4-Dihydro-2H-pyrrole-2-carbonitriles: Useful Intermediates in the Synthesis of Fused Pyrroles and 2,2′-Bipyrroles

Various heterocyclic structures containing the pyrrole moiety have been synthesized from easily accessible 3,4-dihydro-2H-pyrrole-2-carbonitriles in one-pot procedures. 5,6,7,8-Tetrahydroindolizines, 2,3-dihydro-1H-pyrrolizines as well as 6,7,8,9-tetrahydro-5H-pyrrolo[1,2-a]azepines were obtained from these precursors in high yields in an alkylation/annulation sequence. The same conditions were applied in the synthesis of a 5,8-dihydroindolizine, which could easily be transformed to the corresponding indolizine by dehydrogenation. Furthermore, oxidative couplings of 3,4-dihydro-2H-pyrrole-2-carbonitriles with copper(II)-salts furnished 2,2'-bipyrroles as well as 5,5'-bis(5-cyano-1-pyrroline…

A short and modular approach towards 3,5-disubstituted indolizidine alkaloids.

3,5-Dialkyl indolizidines have been prepared in four linear steps from commercially available starting materials. The sequence involves two direct α-functionalization steps and a subsequent reductive amination and provides diastereoselective access to both C-3 epimers of the 5,9-trans-substituted indolizines. The naturally occurring indolizidines 195B and 223AB have been synthesized using this methodology.

Synthesis of Piperidines and Dehydropiperidines

Abstract The present review focuses on strategies for the construction of piperidines and dehydropiperidines, which have appeared in the literature since 2003/2004 through mid-2016. Synthetic methods involving the construction of the six-membered ring from essentially acyclic starting materials in intra- or intermolecular will be highlighted and discussed. In contrast, methods using only the decoration or modification of previously generated pyridines or piperidines will not be part of this review. The published syntheses will be categorized based on the topology of the bond forming events generating the piperidine core.

Visible-Light Organophotoredox-Catalyzed Synthesis of Precursors for Horner-Type Olefinations

CCDC 1483912: Experimental Crystal Structure Determination

Related Article: Marco M. Nebe, Murat Kucukdisli, and Till Opatz|2016|J.Org.Chem.|81|4112|doi:10.1021/acs.joc.6b00393