81555-45-5Relevant academic research and scientific papers
Indium-trichloride catalyzed Michael reaction of silyl enol ethers with α,β-unsaturated carbonyl compounds under neat condition
Loh, Teck-Peng,Wei, Lin-Li
, p. 7615 - 7624 (1998)
In the presence of a catalytic amount of indium (III) trichloride (InCl3) (20 mol%), ketene silyl enol ethers react quickly with α, β- unsaturated ketones and esters to afford the corresponding Michael adducts in moderate to good yields. Indium(III) trichloride can be recovered and reused without decrease in yields.
Synthesis and structures of air-stable binuclear hafnocene perfluorobutanesulfonate and perfluorobenzenesulfonate and their catalytic application in C-C bond-forming reactions
Li, Ningbo,Zhang, Xiaohong,Xu, Xinhua,Chen, Yun,Qiu, Renhua,Chen, Jinyang,Wang, Xie,Yin, Shuang-Feng
supporting information, p. 2430 - 2440 (2013/10/01)
The two air-stable m2-hydroxy-bridged binuclear hafnocene perfluorobutanesulfonate and perfluorobenzenesulfonate complexes were successfully synthesized. The high catalytic activity and recyclability of these complexes were exemplified for various carbon-carbon bond formation reactions. Compared with our previously reported hafnocene perfluorooctanesulfonate, these complexes show stronger Lewis acidity and better catalytic activity, and should find broad applications in organic synthesis.
Development of N,N-bis(perfluoroalkanesulfonyl)squaramides as new strong Br?nsted acids and their application to organic reactions
Cheon, Cheol Hong,Yamamoto, Hisashi
supporting information; experimental part, p. 4257 - 4264 (2010/07/06)
New strong Br?nsted acids derived from a squaric acid scaffold bearing different perfluoroalkanesulfonyl groups have been developed and applied to several organic reactions. These squaramides are bench-stable and exhibit much higher reactivities in several organic reactions than squaric acid itself. N,N-Bis(trifluoromethanesulfonyl)squaramide 2a was applied to the Mukaiyama aldol reaction and Mukaiyama Michael reaction. Mechanistic studies revealed that the Br?nsted acid might be the predominant catalyst through direct protonation of carbonyl compound by the acid itself rather than the silylated Br?nsted acid. The utility of this acid 2a was further extended to Hosomi-Sakurai allylation of aldehydes and a carbonyl-ene reaction. Furthermore, other squaramides 2b and c bearing longer perfluoroalkyl chains have been developed, which are also bench-stable and displayed similar reactivities with squaramide 2a in several organic reactions.
A new Br?nsted acid derived from squaric acid and its application to Mukaiyama aldol and Michael reactions
Cheon, Cheol Hong,Yamamoto, Hisashi
scheme or table, p. 3555 - 3558 (2009/10/26)
Bis-N-trifluoromethanesulfonyl squaramide was prepared as a new bench-stable strong Br?nsted acid and applied to the Br?nsted acid-catalyzed Mukaiyama aldol and Michael reactions with silyl enol ethers. The resulting Mukaiyama aldol products of aldehydes
Regioselective Robinson annulation realized by the combined use of lithium enolates and aluminum tris(2,6-diphenylphenoxide) (ATPH)
Saito, Susumu,Shimada, Itsuro,Takamori, Yusuke,Tanaka, Michiaki,Maruoka, Keiji,Yamamoto, Hisashi
, p. 1671 - 1681 (2007/10/03)
Michael addition of lithium enolates derived from ketones to a variety of a, β-unsaturated ketones was realized in the presence of aluminum tris(2,6-diphenylphenoxide) (ATPH). In this reaction, ATPH can be used as a carbonyl protector of a, β-unsaturated carbonyl substrates upon complexation, which facilitates the regioselective 1,4-addition of lithium enolates to Michael acceptors. Similarly, dianions of β-dicarbonyl compounds undergo Michael addition smoothly using ATPH as an effective promoter of the reaction. Subsequent regioselective, intramolecular aldol condensation was also demonstrated, leading to bicyclic carbon ring systems. Such systems are difficult to obtain by the Robinson annulation usually performed in protic media.
Organotin Triflate as Practical Catalyst for Michael Addition of Enol Silyl Ethers
Sato, Tsuneo,Wakahara, Yoshiyuki,Otera, Junzo,Nozaki, Hitosi
, p. 9773 - 9782 (2007/10/02)
Dibutyltin bis(triflate) is a mild Lewis acid which catalyzes clean Michael addition of enol silyl ethers.The new catalyst allows to employ various labile acceptors such as methyl vinyl ketone and 2-cyclopentenone which do not undergo smooth reaction with
Reductive Cyclization of Mercurial Enones
Danishefsky, Samuel,Chackalamannil, Samuel,Uang, Biing-Jiun
, p. 2231 - 2232 (2007/10/02)
A series of enones containing pendant isolated olefinic linkages was prepared.Solvomercuration could be conducted specifically at the isolated double bond.Treatment of these systems with sodium trimethoxyborohydride results in reductive cyclization.
