https://scholars.lib.ntu.edu.tw/handle/123456789/612094
DC 欄位 | 值 | 語言 |
---|---|---|
dc.contributor.author | Lam, Jolie | en_US |
dc.contributor.author | Guenther, Benjamin A. R. | en_US |
dc.contributor.author | Farrell, Jeffrey M. | en_US |
dc.contributor.author | Eisenberger, Patrick | en_US |
dc.contributor.author | Bestvater, Brian P. | en_US |
dc.contributor.author | Newman, Paul D. | en_US |
dc.contributor.author | Melen, Rebecca L. | en_US |
dc.contributor.author | Crudden, Cathleen M. | en_US |
dc.contributor.author | Stephan, Douglas W. | en_US |
dc.contributor.author | JEFFREY M. FARRELL | zz |
dc.creator | Lam, Jolie; Guenther, Benjamin A. R.; Farrell, Jeffrey M.; Eisenberger, Patrick; Bestvater, Brian P.; Newman, Paul D.; Melen, Rebecca L.; Crudden, Cathleen M.; Stephan, Douglas W. | - |
dc.date.accessioned | 2022-05-27T07:37:43Z | - |
dc.date.available | 2022-05-27T07:37:43Z | - |
dc.date.issued | 2016 | - |
dc.identifier.uri | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84990070335&doi=10.1039%2fc6dt02202b&partnerID=40&md5=ddba7c1df1f2fd49ae46eaf891c6abc1 | - |
dc.identifier.uri | https://scholars.lib.ntu.edu.tw/handle/123456789/612094 | - |
dc.description.abstract | The carbene derived from (1R,3S)-camphoric acid was used to prepare the borane adduct with Piers' borane 7. Subsequent hydride abstraction gave the borenium cation 8. Adducts with 9-BBN and the corresponding (1R,3S)-camphoric acid-derived carbene bearing increasingly sterically demanding N-substituents (R = Me 9, Et 10, i-Pr 11) and the corresponding borenium cations 12-14 were also prepared. These cations were not active as catalysts in hydrogenation, although 9-11 were shown to undergo carbene ring expansion reactions at 50 °C to give species 15-17. The IBOX-carbene precursors 18 and 19 derived from amino alcohols (S)-valinol and (S)-tert-leucinol (R = i-Pr, t-Bu) were used to prepare borane adducts 20-23. Reaction of the carbenes 1,3-dimethylimidazol-2-ylidene (IMe), 1,3-di-iso-propylimidazol-2-ylidene (IPr) 1-benzyl-3-methylimidazol-2-ylidene (IBnMe), 1-methyl-3-phenylimidazol-2-ylidene (IPhMe) and 1-tert-butyl-3-methylimidazol-2-ylidene (ItBuMe) with diisopinocampheylborane (Ipc2BH) gave chiral adducts: (IMe)(Ipc2BH) 24, (IPr)(Ipc2BH) 25, (IBnMe)(Ipc2BH) 26, (IPhMe)(Ipc2BH) 27, and (ItBuMe)(Ipc2BH) 28. Triazolylidene-type adducts including the (10)-phenyl-9-borabicyclo [3.3.2]decane adduct of 1,3,4-triphenyl-1H-1,2,3-triazolium, rac-29 and the 9-BBN derivative of (S)-2-amino-2′-methoxy-1,1′-binaphthalene-1,2,3-triazolium 34a/b were also prepared. In catalytic studies of these systems, while several species were competent catalysts for imine reduction, in general, low enantioselectivities, ranging from 1-20% ee, were obtained. The implications for chiral borenium cation catalyst design are considered. ? 2016 The Royal Society of Chemistry. | - |
dc.relation.ispartof | DALTON TRANSACTIONS | - |
dc.subject.other | Catalysts; Hydrogenation; Positive ions; Binaphthalenes; Carbenes; Catalyst designs; Hydride abstraction; Methoxy; Ring-expansion reaction; Sterically demanding; Organic compounds | - |
dc.title | Chiral carbene-borane adducts: precursors for borenium catalysts for asymmetric FLP hydrogenations | en_US |
dc.type | journal article | en |
dc.identifier.doi | 10.1039/c6dt02202b | - |
dc.identifier.scopus | 2-s2.0-84990070335 | - |
dc.relation.pages | 15303-15316 | - |
dc.relation.journalvolume | 45 | - |
dc.relation.journalissue | 39 | - |
item.fulltext | no fulltext | - |
item.cerifentitytype | Publications | - |
item.openairetype | journal article | - |
item.openairecristype | http://purl.org/coar/resource_type/c_6501 | - |
item.grantfulltext | none | - |
crisitem.author.dept | Chemistry | - |
crisitem.author.dept | Chemistry | - |
crisitem.author.orcid | 0000-0001-5377-354X | - |
crisitem.author.parentorg | College of Science | - |
crisitem.author.parentorg | College of Science | - |
顯示於: | 化學系 |
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