Ruthenium-mediated regio- and stereoselective alkenylation of pyridine.
J Am Chem Soc. 2003 Apr 23; 125(16):4720-1.JA

Abstract

A novel alkenylation reaction of pyridine is developed. Heating a cationic ruthenium vinylidene complex [CpRu(=C=CHR)(PPh(3))(2)]PF(6) in pyridine at 100-125 degrees C for 24 h affords (E)-2-alkenylpyridine. Initially, pyridine coordinates to ruthenium by displacement of one of the phosphine ligands. Then, [2 + 2] heterocycloaddition occurs to form a four-membered ruthenacyclic complex. Deprotonation of the beta-hydrogen affords a neutral pi-azaallyl complex. Protonolysis furnishes the product. As a result, a vinylidene group is inserted into the alpha C-H bond of pyridine. The alkenylation reaction is made catalytic in ruthenium by the use of (alkyn-1-yl)silane as the vinylidene source. Treatment of (alkyn-1-yl)trimethylsilane with pyridine in the presence of a cationic ruthenium complex [CpRu(PPh(3))(2)]PF(6) affords the corresponding (E)-2-alkenylpyridine in good yield in a regio- and stereoselective manner.

Authors+Show Affiliations

Murakami M

Department of Synthetic Chemistry, Kyoto University, Yoshida, Kyoto 606-8501, Japan.

Hori S

No affiliation info available

MeSH

AlkenesAlkynesCatalysisOrganometallic CompoundsPyridinesRutheniumSilanesStereoisomerism

Pub Type(s)

Journal Article

Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

12696885

Citation

Murakami, Masahiro, and Seiji Hori. "Ruthenium-mediated Regio- and Stereoselective Alkenylation of Pyridine." Journal of the American Chemical Society, vol. 125, no. 16, 2003, pp. 4720-1.

Murakami M, Hori S. Ruthenium-mediated regio- and stereoselective alkenylation of pyridine. J Am Chem Soc. 2003;125(16):4720-1.

Murakami, M., & Hori, S. (2003). Ruthenium-mediated regio- and stereoselective alkenylation of pyridine. Journal of the American Chemical Society, 125(16), 4720-1.

Murakami M, Hori S. Ruthenium-mediated Regio- and Stereoselective Alkenylation of Pyridine. J Am Chem Soc. 2003 Apr 23;125(16):4720-1. PubMed PMID: 12696885.

* Article titles in AMA citation format should be in sentence-case

TY - JOUR T1 - Ruthenium-mediated regio- and stereoselective alkenylation of pyridine. AU - Murakami,Masahiro, AU - Hori,Seiji, PY - 2003/4/17/pubmed PY - 2003/6/17/medline PY - 2003/4/17/entrez SP - 4720 EP - 1 JF - Journal of the American Chemical Society JO - J Am Chem Soc VL - 125 IS - 16 N2 - A novel alkenylation reaction of pyridine is developed. Heating a cationic ruthenium vinylidene complex [CpRu(=C=CHR)(PPh(3))(2)]PF(6) in pyridine at 100-125 degrees C for 24 h affords (E)-2-alkenylpyridine. Initially, pyridine coordinates to ruthenium by displacement of one of the phosphine ligands. Then, [2 + 2] heterocycloaddition occurs to form a four-membered ruthenacyclic complex. Deprotonation of the beta-hydrogen affords a neutral pi-azaallyl complex. Protonolysis furnishes the product. As a result, a vinylidene group is inserted into the alpha C-H bond of pyridine. The alkenylation reaction is made catalytic in ruthenium by the use of (alkyn-1-yl)silane as the vinylidene source. Treatment of (alkyn-1-yl)trimethylsilane with pyridine in the presence of a cationic ruthenium complex [CpRu(PPh(3))(2)]PF(6) affords the corresponding (E)-2-alkenylpyridine in good yield in a regio- and stereoselective manner. SN - 0002-7863 UR - https://www.unboundmedicine.com/medline/citation/12696885/Ruthenium_mediated_regio__and_stereoselective_alkenylation_of_pyridine_ DB - PRIME DP - Unbound Medicine ER -

Tags

Ruthenium-mediated regio- and stereoselective alkenylation of pyridine.J Am Chem Soc. 2003 Apr 23; 125(16):4720-1.JA