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Rhodium-catalyzed reductive cyclization of 1,6-diynes and 1,6-enynes mediated by hydrogen: catalytic C-C bond formation via capture of hydrogenation intermediates.
J Am Chem Soc. 2004 Jun 30; 126(25):7875-80.JA

Abstract

Catalytic hydrogenation of carbon-, nitrogen- and oxygen-tethered 1,6-diynes 1a-9a and 1,6-enynes 10a-18a using cationic Rh(I) precatalysts at ambient temperature and pressure enables reductive carbocyclization to afford 1,2-dialkylidene cyclopentanes 1b-9b and monoalkylidene cyclopentanes 10b-18b, respectively, in good to excellent yields and as single alkene stereoisomers. Notably, the 1,3-diene and alkene containing cyclization products 1b-9b and 10b-18b are not subject to over-reduction under the conditions of catalytic hydrogenation in which they are formed. Reductive cyclization 1,6-diyne 1a and 1,6-enyne 10a performed under an atmosphere of D(2) provides the carbocyclization products deuterio-1b and deuterio-10b, respectively, which incorporate two deuterium atoms. The collective data are consistent with a catalytic mechanism involving heterolytic activation of elemental hydrogen (H(2) + Rh(+)X(-) --> Rh-H + HX) followed by Rh(I)-mediated oxidative cyclization of the 1,6-diyne or 1,6-enyne substrates to afford (hydrido)Rh(III)-based metallocyclopentadiene and metallocyclopentene intermediates, respectively. These transformations represent the first examples of metal-catalyzed reductive carbocyclization mediated by hydrogen.

Authors+Show Affiliations

University of Texas at Austin, Department of Chemistry and Biochemistry, Austin, Texas 78712, USA.No affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

15212535

Citation

Jang, Hye-Young, and Michael J. Krische. "Rhodium-catalyzed Reductive Cyclization of 1,6-diynes and 1,6-enynes Mediated By Hydrogen: Catalytic C-C Bond Formation Via Capture of Hydrogenation Intermediates." Journal of the American Chemical Society, vol. 126, no. 25, 2004, pp. 7875-80.
Jang HY, Krische MJ. Rhodium-catalyzed reductive cyclization of 1,6-diynes and 1,6-enynes mediated by hydrogen: catalytic C-C bond formation via capture of hydrogenation intermediates. J Am Chem Soc. 2004;126(25):7875-80.
Jang, H. Y., & Krische, M. J. (2004). Rhodium-catalyzed reductive cyclization of 1,6-diynes and 1,6-enynes mediated by hydrogen: catalytic C-C bond formation via capture of hydrogenation intermediates. Journal of the American Chemical Society, 126(25), 7875-80.
Jang HY, Krische MJ. Rhodium-catalyzed Reductive Cyclization of 1,6-diynes and 1,6-enynes Mediated By Hydrogen: Catalytic C-C Bond Formation Via Capture of Hydrogenation Intermediates. J Am Chem Soc. 2004 Jun 30;126(25):7875-80. PubMed PMID: 15212535.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Rhodium-catalyzed reductive cyclization of 1,6-diynes and 1,6-enynes mediated by hydrogen: catalytic C-C bond formation via capture of hydrogenation intermediates. AU - Jang,Hye-Young, AU - Krische,Michael J, PY - 2004/6/24/pubmed PY - 2004/6/24/medline PY - 2004/6/24/entrez SP - 7875 EP - 80 JF - Journal of the American Chemical Society JO - J Am Chem Soc VL - 126 IS - 25 N2 - Catalytic hydrogenation of carbon-, nitrogen- and oxygen-tethered 1,6-diynes 1a-9a and 1,6-enynes 10a-18a using cationic Rh(I) precatalysts at ambient temperature and pressure enables reductive carbocyclization to afford 1,2-dialkylidene cyclopentanes 1b-9b and monoalkylidene cyclopentanes 10b-18b, respectively, in good to excellent yields and as single alkene stereoisomers. Notably, the 1,3-diene and alkene containing cyclization products 1b-9b and 10b-18b are not subject to over-reduction under the conditions of catalytic hydrogenation in which they are formed. Reductive cyclization 1,6-diyne 1a and 1,6-enyne 10a performed under an atmosphere of D(2) provides the carbocyclization products deuterio-1b and deuterio-10b, respectively, which incorporate two deuterium atoms. The collective data are consistent with a catalytic mechanism involving heterolytic activation of elemental hydrogen (H(2) + Rh(+)X(-) --> Rh-H + HX) followed by Rh(I)-mediated oxidative cyclization of the 1,6-diyne or 1,6-enyne substrates to afford (hydrido)Rh(III)-based metallocyclopentadiene and metallocyclopentene intermediates, respectively. These transformations represent the first examples of metal-catalyzed reductive carbocyclization mediated by hydrogen. SN - 0002-7863 UR - https://www.unboundmedicine.com/medline/citation/15212535/Rhodium_catalyzed_reductive_cyclization_of_16_diynes_and_16_enynes_mediated_by_hydrogen:_catalytic_C_C_bond_formation_via_capture_of_hydrogenation_intermediates_ L2 - https://doi.org/10.1021/ja048498i DB - PRIME DP - Unbound Medicine ER -
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