2024-03-28T08:55:51Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:00024857
2023-01-16T04:15:22Z
1903:1904:1905
Combined Experimental and Computational Study on Ruthenium(II)-Catalyzed Reactions of Diynes with Aldehydes and N,N‑Dimethylformamide
Yoshihiko, Yamamoto
Yuta, Okude
Shota, Mori
Masatoshi, Shibuya
open access
“This document is the Accepted Manuscript version of a Published Work that appeared in final form in [Journal of Organic Chemistry], copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see [ http://pubs.acs.org/articlesonrequest/AOR-gsXP3SHHURzcsmdS3cwp].”
Cycloaddition reactions of 1,6-diynes bearing methyl terminal groups with p-anisaldehyde were conducted using a cationic ruthenium catalyst with a η^5 -pentamethylcyclopentadienyl ligand in THF at room temperature to afford dienyl ketones via ring opening of the initially formed fused pyrans. (Z)-Stereoisomers of dienyl ketones were selectively obtained using the ruthenium catalyst, whereas previously reported rhodium catalysts produced (E)-isomers. These (E)- and (Z)-selectivities are kinetically controlled as the control experiments showed that the E/Z-isomerization of (E)-dienylketone occurs at 70 °C for 10 h to afford an E/Z-ratio of almost 1:1. The origin of this characteristic stereoselectivity for the ruthenium catalyst was attributed to the direct ring opening of the CpRu^+ -coordinated pyran complex intermediates on the basis of theoretical calculations [PCM (THF) M06L/SDD-6-311++G(d,p)//B3LYP/LanL2DZ-6-31G(d)] and control experiments. The (Z)-selectivity increased when the bulkiness of the diyne terminal substituents increased. Notably, the reaction of 1,6-diynes bearing tert-butyl terminal groups with various α,β-unsaturated aldehydes exclusively afforded (Z)-dienyl ketones even at 70 °C when a cationic ruthenium complex with a smaller η^5 -cyclopentadienyl (Cp) ligand was used as the catalyst. The same Cp complex was found to be also efficient for the hydrocarbamoylative cyclization of sterically demanding 1,6-diynes bearing tertiary or quaternary carbon tethers with N,N-dimethylformamide.
ACS Publications
2017-08-04
eng
journal article
AM
http://hdl.handle.net/2237/27077
https://nagoya.repo.nii.ac.jp/records/24857
https://doi.org/10.1021/acs.joc.7b01229
0022-3263
Journal of Organic Chemistry
82
15
7964
7973
https://nagoya.repo.nii.ac.jp/record/24857/files/JOC_MS_rev.pdf
application/pdf
895.1 kB
2018-08-04