86767-33-1Relevant academic research and scientific papers
Synthesis and application of 2,6-bis(trifluoromethyl)-4-pyridyl phosphanes: The most electron-poor aryl phosphanes with moderate bulkiness
Korenaga, Toshinobu,Ko, Aram,Uotani, Kotaro,Tanaka, Yuki,Sakai, Takashi
supporting information; experimental part, p. 10703 - 10707 (2012/01/04)
The poor will be rich: BFPy phosphanes (see scheme) mimic the electronic and steric characters of P(C6F5)3 and PPh 3, respectively. These novel ligands showed a large ligand acceleration effect on Stille coupling, the Rh-catalyzed 1,2-addition of aryl boronic acid to unactivated ketones and the asymmetric arylation of N-tosylimine using phenylboronic acid. Copyright
A nickel catalyst for the addition of organoboronate esters to ketones and aldehydes
Bouffard, Jean,Itami, Kenichiro
supporting information; scheme or table, p. 4410 - 4413 (2009/12/26)
A Ni(cod)2/IPr catalyst promotes the intermolecular 1,2-addition of arylboronate esters to unactivated aldehydes and ketones. Dlaryl, alkyl aryl, and dialkyl ketones show good reactivity under mild reaction conditions (3) with aryl ether substrates. A Ni(0)/Ni(II) catalytic cycle initiated by the oxidative cyclization of the carbonyl substrate Is proposed.
Highly enantioselective arylation of aldehydes and ketones using AlArEt2(THF) as aryl sources
Zhou, Shuangliu,Wu, Kuo-Hui,Chen, Chien-An,Gau, Han-Mou
supporting information; experimental part, p. 3500 - 3505 (2009/09/30)
A series of AlArEt2(THF) (Ar = Ph (la), 4-MeC6H 4 (1b), 4-MeOC6H 4 (1c), 4-Me 3SiC6H4 (1d), 2-naphthyl (le)) were synthesized from reactions of AlEt2Br(THF) with ArMgBr. In CDC13 solution, the 1H NMR spectra showed that AlArEt2(THF) compounds exist as a mixture of four species of formulas of AlAr xEt3-x (THF) (x = 0, 1, 2, or 3). AlArEt2(THF) compounds were found to be superior and atom-economic reagents for asymmetric aryl additions to organic carbonyls. Aryl additions of AlArEt2(THF) to aldehydes catalyzed by the titanium(IV) complex of (R)-H8-BINOL were efficient with a short reaction time of 1 h, affording aryl addition products as exclusive or main products in high yields and excellent enantioselectivities of up to 98% ee. Although ethyl additions to aldehydes occurred in minor extent, this study demonstrates that increasing the amount of AlArEt2(THF) from 1.2 to 1.4 or to 1.6 equiv significantly improved the aryl addition products of up to >99%. On the other hand, asymmetric arylations of AlArEt2(THF) to ketones employing a titanium(IV) catalyst of (S)-BINOL produced optically active tertiary alcohols exclusively in excellent enantioselectivities of up to 94% ee.
Transition-State Polarization in Cleavage of C-C Bonds in Radical Anions
Maslak, Przemyslaw,Narvaez, Javier N.,Kula, Jozef,Malinski, David S.
, p. 4550 - 4559 (2007/10/02)
The substituent effect on the rate of C-C bond cleavage in radical anions of 1-(4-nitrophenyl)-2-(substituted-phenyl)-1,1,2,2-tetraethylethanes has been explored.The data provide evidence for two distinctive modes of bond scission.One mode is characterized by a significant negative charge transfer across the scissile bond in the transition state.Such polarization of the transition state is in contradiction to the prediction based on the fragments' stability.The second mode, dominant in cases where the charge shift leads to negative charge accumulation on an already electron-rich fragment, involves a ?* radical anion.Both modes point to a general kinetic preference for a cleavage of radical anions that allows for charge delocalization across the scissile bond.
