18666-25-6Relevant academic research and scientific papers
Catalytic asymmetric alkylation of acylsilanes
Rong, Jiawei,Oost, Rik,Desmarchelier, Alaric,Minnaard, Adriaan J.,Harutyunyan, Syuzanna R.
, p. 3038 - 3042 (2015)
The highly enantioselective addition of Grignard reagents to acylsilanes is catalyzed by copper diphosphine complexes. This transformation affords α-silylated tertiary alcohols in up to 97% yield and 98:2 enantiomeric ratio. The competing Meerwein-Ponndorf-Verley reduction is suppressed by the use of a mixture of Lewis acid additives. The chiral catalyst can be recovered as a copper complex and used repeatedly without any loss of catalytic activity.
Tertiary α-Silyl Alcohols by Diastereoselective Coupling of 1,3-Dienes and Acylsilanes Initiated by Enantioselective Copper-Catalyzed Borylation
Feng, Jian-Jun,Oestreich, Martin
supporting information, p. 8211 - 8215 (2019/05/27)
An efficient synthesis of functionalized tertiary α-silyl alcohols by an enantio- and diastereoselective copper-catalyzed three-component coupling of 1,3-dienes, bis(pinacolato)diboron, and acylsilanes is reported. The reaction proceeds well with different 1,3-dienes and a broad range of aryl- as well as alkenyl- but also alkyl-substituted acylsilanes. The target compounds are formed with high regio-, diastereo-, and enantioselectivity (up to 99 % ee and d.r. >20:1) and are highly versatile synthetic building blocks.
Enantioselective Synthesis of Chiral 3-Substituted-3-silylpropionic Esters via Rhodium/Bisphosphine-Thiourea-Catalyzed Asymmetric Hydrogenation
Zhang, Zongpeng,Han, Zhengyu,Gu, Guoxian,Dong, Xiu-Qin,Zhang, Xumu
supporting information, p. 2585 - 2589 (2017/08/16)
We have successfully developed the asymmetric hydrogenation of β-silyl-α,β-unsaturated esters to prepare chiral 3-substituted-3-silylpropionic ester products catalyzed by rhodium/bisphosphine-thiourea (ZhaoPhos) with excellent results (up to 97% yield, >99% ee, 1500 TON). Moreover, our hydrogenation products can be efficiently converted to other important organic molecules, such as chiral ethyl (R)-3-hydroxy-3-phenylpropanoate or (R)-3-[dimethyl(phenyl)silyl]-3-phenylpropanoic acid. (Figure presented.).
Synthesis of Optically Pure Arylsilylcarbinols and Their Use as Chiral Auxiliaries in Oxacarbenium Ion Reactions
Huckins, John R.,Rychnovsky, Scott D.
, p. 10135 - 10145 (2007/10/03)
A family of arylsilylcarbinols was synthesized and investigated as chiral auxiliaries for oxacarbenium ion reactions. The optically pure arylsilylcarbinols were prepared using Noyori's transfer hydrogenation catalyst 11. The transfer hydrogenation shows very good enantioselectivities and turnover efficiency for the aryl silyl ketones and is the method of choice for preparing these optically pure alcohols. The diastereoselective addition of allyltrimethylsilane to an in situ generated oxacarbenium ion was explored using Marko's conditions. The selectivity for a representative aliphatic aldehyde was very good, but the selectivity was significantly reduced with unsaturated and aromatic aldehydes. The range of selectivities with different auxiliaries was narrow, and the most practical auxiliary is the phenylsilylcarbinol 2.
The magnesium-ene cyclization stereochemically directed by an allylic oxyanionic group and its application to a highly stereoselective synthesis of (±)-matatabiether. Allylmagnesium compounds by reductive magnesiation of allyl phenyl sulfides
Cheng,Zhu,Yu,Cohen
, p. 30 - 34 (2007/10/03)
The first example of a magnesium-ene cyclization stereochemically directed by an allylic oxyanionic group is demonstrated by a highly stereoselective synthesis of the bicyclic terpene matatabiether 10. The synthetic method is particularly valuable, not only because of the stereochemical control and the utility of the versatile hydroxyl group introduced into the product, but also because the precursor of the allylmagnesium is an allyl phenyl sulfide, which is more stable and more easily prepared in a connective fashion than the usual allyl halide precursor. Since the presence of lithium ions encourages undesirable proton transfer to the cyclized organometallic and is detrimental to the stereochemical control, the conversion of the allylic thioether to the allylmagnesium utilizes a lithium-free method involving direct reductive magnesiation in the presence of the magnesium-anthracene complex.
Efficient formation and cleavage of disilanes by potassium-graphite. Silylation with silyl metal reagents
Fuerstner, Alois,Weidmann, Hans
, p. 15 - 22 (2007/10/02)
Potassium-graphite laminate (C8K) very rapidly forms disilanes from chlorosilanes and then rapidly cleaves the disilanes to give silyl potassium reagents which can be converted into potassium silyl cuprates, -manganates, and -vanadates that are useful for various nucleophilic substitution and addition reactions.
SUBSTITUENT EFFECTS OF SOME ORGANOSILYLMETHYL GROUPS
Eaborn, Colin,Hancock, Alan R.,Stanczyk, Wlodzimierz A.
, p. 147 - 154 (2007/10/02)
The charge transfer frequencies for some tetracyanoethylene-PhX complexes have been used to derive ?+p constants and 13C NMR data to derive ?0R constants for the X groups, with the following results (X, -?+
