Ruthenium-Complex-Catalyzed Regio- and Stereoselective Linear Codimerization of 2-Norbornenes with Acrylic Compounds

Abstract

A linear codimerization of 2-norbornenes with acrylic compounds such as acrylates and an acrylamide proceeded efficiently by ruthenium catalyst systems, RuCl3(tpy)/Zn (tpy = 2,2':6',2' '-terpyridine) or [RuCl2(C6H6)]2/Zn in a primary or secondary alcoholic solvent, to afford the corresponding exo-trans-2-norbornylacrylates as major products regio- and stereoselectively along with a small amount of cis isomers. The reaction of 2,5-norbornadiene with methyl acrylate also gave the linear exo-trans codimer, which was effectively catalyzed by the addition of triarylphosphines to the RuCl3(tpy)/Zn catalyst system.

Regio‐ and Stereoselective Synthesis of Enamides and Dienamides by Ruthenium‐Catalyzed Co‐Oligomerization of N‐Vinylamides with Alkenes or Alkynes

“…In sharp contrast, a codimerization reaction of "different alkenes" is still quite difficult except for hydrovinylation [13] and a challenging subject in modern organic and organometallic chemistry. [14] Herein we report zero-valent ruthenium-catalyzed codimerization reaction of different alkenes, that is, a codimerization reaction of N-vinylamides with alkenes as well as a cooligomerization reaction of N-vinylamides, acrylates, and ethylene, which offer novel and atom-economical methods for the synthesis of enamides with high regio-and stereoselectivity in one step. [15,16] As expected, the present catalyst system can be applied to the codimerization of N-vinylamides with alkynes, which enables the selective synthesis of dienamides.…”

Heterodimerization of Olefins: A Highly Promising Strategy for the Selective Synthesis of Functionalized Alkenes

“…A new synthetic strategy is currently emerging as an alternative to these methods, which are all limited in one way or another: the Ru‐catalyzed dimerization of two different olefins 19. 20 The recently published initial examples were surprising insofar as a successful selective heterodimerization of two alkenes requires that the homodimerization of each reaction partner is effectively suppressed and oligomerizations essentially do not occur. A special case for this has been known for some time, the Ni‐catalyzed codimerization of alkenes with ethene, which is used preparatively in hydrovinylations 21.…”

“…were able to extend the method to the important class enamides (Scheme ). They treated N ‐vinyl amides with other different olefins to form E ‐configured, linear enamides in moderate yields and with good stereoselectivities 20. A particular advantage with respect to their use in synthesis is that unlike more complex enamides, N ‐vinyl amides are readily available since they are used industrially as monomers for (co)polymerizations.…”

Highly Selective Dimerization of Styrenes and Linear Co‐dimerization of Styrenes with Ethylene Catalyzed by a Ruthenium Complex

“…[10,11] The products are head-to-tail dimers (3-aryl-1-butenes), and an enantioselective version of the co-dimerization (hydrovinylation) of styrenes with ethylene has recently been developed. [11,12] In the course of our study on the synthesis and catalytic activity of low-valent ruthenium complexes [13] as well as ruthenium-catalyzed co-dimerization reactions of different alkenes, [14] we found that the zero-valent ruthenium complex…”