Detail of "75968-40-0"

Reference

Chiral Metallocenes

3. The Enantioselective Reduction of C:X Bonds (X = O or CH2) by the Chiral ansa-Metallocenes (R)- or (S)-[TiCl2(h5:h5- C5Me4SiMe2C5H3R)] (R = Menthyl or Neomenthyl). Beagley, Paul; Davies, Philip J.; Blacker, A. John; White, Colin ( Department of Chemistry, University of Sheffield, Sheffield S3 7HF, UK). Organometallics, 21(26), 5852-5858 (English) 2002 American Chemical Society. CODEN: ORGND7. ISSN: 0276-7333. DOCUMENT TYPE: Journal CA Section: 29 (Organometallic and Organometalloidal Compounds) Section cross-reference(s): 75 After activating with n-BuLi, the two diastereoisomers of [TiCl2(h5:h5-C5Me4SiMe2C5H3R*)] (1a, R* = menthyl), which have different faces of the asym. cyclopentadienyl ring coordinated to the titanium, catalyze the hydrosilylation of ketones, with the (1a)R diastereomer being more enantioselective than the (1a)S isomer.In this article, certain chemicals are used. Some of their cas registry numbers are 75968-40-0 and 51154-54-2 For example, with the (1a)R catalyst, hydrosilylation of acetophenone gives, after hydrolysis, S-PhCH(OH)Me in 82% ee, whereas only 16% ee of R-PhCH(OH)Me is obtained with the corresponding (1a)S catalyst. Inspection of the crystal structures of both (1a)R and (1a)S allows this difference in stereoselectivity to be rationalized. Highest ee's and rates of hydrosilylation were obsd. with aryl ketones contg. electron-donating groups in the ring. The diastereoisomer (1a)R catalyzes the hydrogenation of alkenes; thus, 2-phenyl-1-butene, PhC(Et):CH2, is hydrogenated in 53% ee (S). The same redn. carried out with a 1.4:1 mixt. of R and S diastereoisomers of the corresponding TiCl2(h5:h5-C5Me4SiMe2C5H3R*) (1b, R* = neomenthyl) gives 36% ee of R-PhCH(Me)Et. .

Ru-(phosphine-oxazoline) complexes as effective, industrially viable catalysts for the enantioselective hydrogenation of aryl ketones

Naud, Frederic; Malan, Christophe; Spindler, Felix; Ruggeberg, Carsten; Schmidt, Andreas T.; Blaser, Hans-Ulrich (Solvias AG, Basel 4002, Switz.). Advanced Synthesis & Catalysis, 348(1 + 2), 47-50 (English) 2006 Wiley-VCH Verlag GmbH & Co. KGaA. CODEN: ASCAF7. ISSN: 1615-4150. DOCUMENT TYPE: Journal CA Section: 25 (Benzene, Its Derivatives, and Condensed Benzenoid Compounds) Complexes prepd. in situ from RuCl2(PPh3)3 and chiral phosphine-oxazoline ligands are effective catalysts for the hydrogenation of various aryl ketones R1COR2 (R1 = Ph, 2-ClC6H4, 4-MeOC6H4, etc.; R2 = Me, Et, Me2CH) with ees up to 99% and substrate to catalyst ratios of 10,000-50,000; the reaction tolerates high substrate concns. 98-86-2 and 75968-40-0 which are cas registry numbers of substances are two of reagents here. and a pilot process has been developed for the hydrogenation of 3,5-bis(trifluoromethyl)acetophenone. .