32102-32-2

Upstream product

• 15842-76-9 (2-chloro-phenyl)-trimethyl-silane 
• 98-86-2 acetophenone 
• 694-80-4 2-bromo-1-chlorobenzene 
• 2142-68-9 1-(2-chlorophenyl)ethanone 
• 100-58-3 phenylmagnesium bromide 
• 917-54-4 methyllithium 

Relevant academic research and scientific papers

Highly enantioselective arylation of aldehydes and ketones using AlArEt2(THF) as aryl sources

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.

Electron Transfer in Reactions of Ketones with Organolithium Reagents. A Carbon-14 Kinetic Isotope Effect Probe

Kinetic isotope effects have been determined for reactions of ketones labeled with carbon-14 at the carbonyl carbon with MeLi and Me2CuLi in diethyl ether at 0 deg C.Observed isotope effects were as follows: (C6H5)2C=O + MeLi, 12k/14k = 1.000 +/- 0.002; (C6H5)2C=O + Me2CuLi, 1.029 +/- 0.005; 2,4,6-Me3C6H2COC6H5 + MeLi, 1.023 +/- 0.004.The relative reactivities of ortho-, meta-, and para-substituted benzophenones with these reagents were also determined by the competition experiments.These results are consistent with an electron transfer step which is followed by a carbon-carbon bond-formimg step that is or is not rate determining depending on the structure of ketones and reagents.The reaction of benzophenone with MeLi proceeds via rate-determining electron transfer; the change in nucleophile from MeLi to Me2CuLi shifts the rate-determining step from electron-transfer to recombination; the change in ketone from benzophenone to 2,4,6-trimethylbenzophenone also shifts the rate-determining step from electron transfer to recombination because the latter step becomes slower for the more hindered ketone.The extent of the geometrical change of the substrate at the electron-transfer transition state of the reaction of benzophenone with MeLi was estimated to be small on the basis of the magnitude of the KIE and teh ρ value of the Hammett correlation.

Hydroxyalkylation, Acylation, Formylation, and Carboxylation of 2-Nitro- and 2-Chloro-1-(trimethylsilyl)benzene

The synthetic application of base-catalyzed carbodesilylation of aryltrimethylsilanes is demonstrated in the reactions of 2-nitro- (1a) and 2-chloro-1-(trimethylsilyl)benzene (1b) with aldehydes, ketones, acyl fluorides and carboxylic anhydrides, respectively, dimethylformamide, and carbon dioxide.The corresponding benzenes 3 and 8, (hydroxyalkyl)benzenes 4, 6, and 9, the benzophenones 12, the benzaldehydes 14, and the benzoic acids 17 are obtained in good yields.The new method is a useful alternative to the normal electrophilic substitution or the application of organometallic compounds, respectively, for the synthesis of polysubstituted benzenes.