135348-18-4

Upstream product

• 18162-48-6 tert-butyldimethylsilyl chloride 
• 13704-09-1 (S)-(-)-ethyl mandelate 
• 78324-07-9 α-<(tert-butyldimethylsiloxy)phenyl>acetyl tert-butydimethylsilyl ester 
• 774-40-3 hydroxy-phenyl-acetic acid ethyl ester 
• 64-17-5 ethanol 
• 105041-07-4 (tert-Butyl-dimethyl-silanyloxy)-phenyl-acetyl bromide 
• 325465-01-8 (S)-(4-amino-phenyl)-(tert-butyl-dimethyl-silanyloxy)-acetic acid ethyl ester 
• 325464-82-2 (S)-2-[4-(dimethylamino)phenyl]-2-hydroxyacetic acid ethyl ester 
• 69739-34-0 t-butyldimethylsiyl triflate 

Downstream Products

• 155671-23-1 (S)-1-(tert-Butyl-dimethyl-silanyloxy)-1-phenyl-3-((R)-toluene-4-sulfinyl)-propan-2-one 
• 133187-22-1 (2S)-2-(tert-butyldimethylsilyloxy)-2-phenylacetaldehyde 
• 898567-43-6 (-)-(2S)-1-(4-bromothiazol-2-yl)-2-(t-butyldimethylsilyloxy)-2-phenylethanone 
• 10606-72-1 (R)-mandelic acid ethyl ester 
• 13704-09-1 (S)-(-)-ethyl mandelate 
• 898567-47-0 (+)-(1S,2S)-2-azido-2-(4-bromothiazol-2-yl)-1-phenylethanol 
• 898567-46-9 (+)-(1R,2S)-methanesulfonic acid 1-(4-bromothiazol-2-yl)-2-hydroxy-2-phenylethyl ester 
• 898567-49-2 (-)-(1S,2S)-1-(4-bromothiazol-2-yl)-2-(t-butyldimethylsilyloxy)-2-phenylethylamine 
• 898567-44-7 (+)-(1R,2S)-1-(4-bromothiazol-2-yl)-2-(tert-butyldimethylsilyloxy)-2-phenylethanol 
• 898567-48-1 (+)-(1S,2S)-2-[1-azido-2-(tert-butyldimethylsilyloxy)-2-phenylethyl]-4-bromothiazole 
• 898567-45-8 (+)-(1R,2S)-methanesulfonic acid 1-(4-bromothiazol-2-yl)-2-(tert-butyldimethylsilyloxy)-2-phenylethyl ester 
• 135560-64-4 (3R,4S)-3-ethyl-4-<(S)-1-hydroxymethylphenyl>-2-azetidinone 
• 135560-68-8 (3R,4S)-3-isopropyl-4-<(S)-1-hydroxymethylphenyl>-2-azetidinone 
• 174513-18-9 (S)-2-<(tert-butyldimethylsilyl)oxy>-2-phenyl-N-(trimethylsilyl)ethanimine 

Relevant academic research and scientific papers

The influence of α-coordinating groups of aldehydes on E/Z-selectivity and the use of quaternary ammonium counter ions for enhanced E-selectivity in the Julia–Kocienski reaction

Modified reaction conditions for improved E-selectivity of olefins in the Julia–Kocienski reaction of aldehydes having α-coordinating substituents are demonstrated. The chelating groups in aldehydes are expected to stabilize the syn-transition state with metal ions, whereas the weakly coordinating quaternary ammonium ions are devoid of all possible chelating interactions to enhance E-selectivity. A systematic investigation is presented to study the size of the neighbouring protecting groups of aldehydes and their chelation effect on E/Z-selectivity in the Julia–Kocienski reaction.

The rhodium-catalyzed carbene cyclization cycloaddition cascade reaction of vinylsulfonates

Vinylsulfonates have proved to be excellent dipolarophiles for carbonyl ylides derived from diazoketones in rhodium-catalyzed intramolecular cycloadditions. Polyfunctional substrates, such as 8 and (+)-15, were readily available from hydroxy esters, e.g. 1 and the cyclopenta-1,3-dione 10, respectively, and the resulting polycyclic sultones were formed under mild reaction conditions in high yields with very good diastereoselectivities. A ruthenium-catalyzed asymmetric transfer hydrogenation was found to desymmetrize the meso-cyclopenta-1,3-dione 12 efficiently.

Synthesis of 3-fluorofuran-2(5H)-ones based on Z/E photoisomerisation and cyclisation of 2-fluoro-4-hydroxybut-2-enoates

Mixtures of some (E)- and (Z)-2-fluoroalk-2-enoates prepared from the corresponding 2-hydroxycarbonyl compounds and ethyl 2-(diethoxyphosphoryl)-2- fluoroacetate have been transformed in high conversions into the target 3-fluorofuran-2(5H)-ones by an effi

Comparative Study of the Diastereoselective Addition of Allenyl Zinc Reagents to α-Alkoxy (or Silyloxy) Aldehydes and Imines. A Straightforward Synthesis of Amino Alcohols from Imines

The addition of allenylzinc bromides to α-chiral imines proceeds with very high diastereoselectivity. This result is in contrast with the addition to the corresponding aldehydes, leading to poor diastereoselectivity. The anti/anti adducts are explained by Felkin-Ahn and Gaudemar-Yamamoto models of the transition state.

Catalytic enantioselective Friedel-Crafts reactions of aromatic compounds with glyoxylate: A simple procedure for the synthesis of optically active aromatic mandelic acid esters

The first catalytic highly enantioselective Friedel-Crafts reaction of aromatic compounds with glyoxylate catalyzed by chiral Lewis acids is presented. The reaction has been developed for mainly aromatic amines reacting with ethyl glyoxylate in the presence of chiral bisoxazoline-copper(II) complexes as the catalyst. A series of chiral bisoxazoline-copper(II) complexes have been tested as catalysts for the reaction with N,N-dimethylaniline and it has been found that a highly regio- and enantioselective Friedel-Crafts reaction takes place in the presence of especially tert-butyl bisoxazoline-copper(II). This reaction proceeds with the formation of exclusively the para-substituted isomer in up to 95% yield and 94% ee. The reaction has been investigated for N,N-dimethylaniline under different reaction conditions and has been developed to be a catalytic highly enantioselective reaction for meta-substituted N,N-dimethylanilines, containing either electron-withdrawing or electron-donating substituents. The catalytic enantioselective Friedel-Crafts reaction also proceeds well for cyclic aromatic amines such as N-methylindoline, N-methyltetrahydroquinoline, and julolidine, where up to 91% yield and 93% ee are obtained. For polyaromatic amines high yields, but moderate ee values, of the Friedel-Crafts products are obtained. To enhance the potential of the reaction the N,N-dimethyl- and N-methyl substituents can be removed successfully leading to either the mono-N-methyl product or the free amine. The latter class of products allow for the introduction of a variety of other substituents on the aromatic nucleus. The catalytic enantioselective reaction also proceeds for heteroaromatic compounds such as 2-substituted furans which react with glyoxylate as well as trifluoropyruvates, giving up to 89% ee of the Friedel-Crafts products. Furthermore, ethyl trifluoropyruvate reacts in a highly enantioselective reaction with m-methoxyanisole to give the corresponding Friedel-Crafts product in good yield. On the basis of the experimental results and the absolute configuration of the products, the mechanism for this catalytic highly enantioselective Friedel-Crafts reaction is presented.

β-Lactams from Ester Enolates and Silylimines: Enantioselective Synthesis of the trans-Carbapenem Antibiotics (+)-PS-5 and (+)-PS-6

A new synthetic route to the antibiotics (+)-PS-5 and (+)-PS-6 is described.The preparation involves a fully stereocontrolled reaction between the enantiomerically pure N-trimethylsilylimine of lactic or mandelic aldehyde and the lithium enolate of the tert-butyl butanoate or tert-butyl isovalerate, respectively.Conversion of the azetidinones obtained to 4-acetoxy derivatives via oxidative cleavage of the hydroxyethyl or hydroxybenzyl side chain and introduction of the necessary appendage in the position 4 of the azetidinone ring, followed by assemlage of the bicyclic ring system, afforded the natural trans-carbapenems (+)-PS-5 and (+)-PS-6.

Reaction of Hindered Trialkylsilyl Esters and Trialkylsilyl Ethers with Triphenylphosphine Dibromide: Preparation of Carboxylic Acid Bromides and Alkyl Bromides under MIld Neutral Conditions

A new route for a simultaneous deprotection-activation of hindered trialkylsilyl esters is described. tert-Butyldimethylsilyl, triisopropylsilyl, and tert-butyldiphenylsilyl carboxylates reacted with triphenylphosphine dibromide at room temperature in dichloromethane to give acid bromides in high yields.Reaction between hindered trialkylsilyl ethers and triphenylphosphine dibromide afforded alkyl bromides in excellent yields.The formation rate of acid bromides and alkyl bromides was increased when the reactions were carried out in the presence of a catalytic amount of ZnBr2.