166450-58-4

Upstream product

• 80522-42-5 triisopropylsilyl trifluoromethanesulfonate 
• 529-34-0 3,4-dihydronaphthalene-1(2H)-one 

Downstream Products

• 334022-35-4 methyl (αR)-[(2S)-4-(triisopropylsilyloxy)-1,2-dihydro-naphthalen-2-yl]-(4-bromo-phenyl)acetate 

Relevant academic research and scientific papers

Intermolecular C-O Bond Formation with Alkoxyl Radicals: Photoredox-Catalyzed α-Alkoxylation of Carbonyl Compounds

Due to the high reactivity of alkoxyl (RO·) radicals and their propensity to easily undergo β-scission or Hydrogen Atom Transfer (HAT) reactions, intermolecular alkoxylations involving RO· radicals are barely described. We report herein for the first time the efficient intermolecular trapping of alkoxyl radicals by silyl enol ethers. This photoredox-mediated protocol enables the introduction of both structurally simple and more complex alkoxy groups into a wide range of ketones and amides.

Asymmetric Oxidation of Enol Derivatives to α-Alkoxy Carbonyls Using Iminium Salt Catalysts: A Synthetic and Computational Study

We report herein the first examples of asymmetric oxidation of enol ether and ester substrates using iminium salt organocatalysis, affording moderate to excellent enantioselectivities of up to 98% ee for tetralone-derived substrates in the α-hydroxyketone products. A comprehensive density functional theory study was undertaken to interpret the competing diastereoisomeric transition states in this example in order to identify the origins of enantioselectivity. The calculations, performed at the B3LYP/6-31G(D) level of theory, gave good agreement with the experimental results, in terms of the magnitude of the effects under the specified reaction conditions, and in terms of the preferential formation of the (R)-enantiomer. Just one of the 30 characterized transition states dominates the enantioselectivity, which is attributed to the adoption of an orientation relative to stereochemical features of the chiral controlling element that combines a CH interaction between a CH2 group in the substrate and one of the aromatic rings of the biaryl section of the chiral auxiliary with a good alignment of the acetoxy group with the other biaryl ring, and places the smallest substituent on the alkene (a hydrogen atom) in the most sterically hindered position.

Chemo- and Regioselective Ring Construction Driven by Visible-Light Photoredox Catalysis: an Access to Fluoroalkylated Oxazolidines Featuring an All-Substituted Carbon Stereocenter

The unique advantages conferred by incorporation of all-substituted carbon stereocenters in organic molecules have gained widespread recognition. In this work, we describe a three-component cyclization to access C-2 fluoroalkylated oxazolidines by fragments assembly of readily available silyl enol ether, fluoroalkyl halide, and chiral amino alcohol in a single reaction vessel, which provides an efficient strategy for expanding the pool of pharmaceutically important heterocycles featuring an all-substituted carbon stereocenter. This process proceeds efficiently in a chemo-, regio-, and stereoselective fashion under mild reaction conditions at room temperature and exhibits broad functional group tolerance. The successful realization of this controlled heteroannulation sequence relies on distinctive perfluoroalkylation, regio- and stereoselective radical cyclization through visible-light photoredox catalysis. Moreover, a one-pot procedure directly employing ketone as substrate has also been achieved. (Figure presented.).

Combining Fluoroalkylation and Defluorination to Enable Formal [3 + 2 + 1] Heteroannulation by Using Visible-Light Photoredox Organocatalysis

A metal-free, visible-light photoredox-catalyzed three-component [3 + 2 + 1] heteroannulation for accessing modular fluoroalkylated pyrimidines from readily available silyl enol ether, amidine, and fluoroalkyl halide is developed. This protocol distinguishes itself by broad functional group tolerance in a regioselective manner, which provides a complement to the existing methods for the construction of pharmaceutically and biologically active organofluorine compounds.

Br?nsted acid-promoted cyclizations of siloxy alkynes with unactivated arenes, alkenes, and alkynes

In this article, we describe the development of a general concept for the development of new carbon-carbon bond-forming processes, which is based on Br?nsted acid-mediated activation of a siloxy alkyne, followed by efficient interception of the resulting highly reactive ketenium ion by unactivated arenes, alkenes or alkynes. We found that trifluoromethane sulfonimide (HNTf2) proved to be a superior promoter of these reactions compared to a range of other Br?nsted acids. This finding could be attributed to a high acidity of HNTf2 in aprotic organic solvents combined with a low nucleophilicity of the NTf2- anion. Depending on the nature of the nucleophile, the carbocyclizations proceeded either via 6-endo-dig or 5-endo-dig manifolds. In the case of 1-siloxy-1,5-diynes, the cyclizations occurred with a concomitant halide abstraction or arylation.

Pd(OH)2/C-mediated selective oxidation of silyl enol ethers by tert-butylhydroperoxide, a useful method for the conversion of ketones to α,β-enones or β-Silyloxy-α,β-enones

(Chemical Equation Presented) Pd(OH)2-catalyzed oxidation of silyl enol ethers by t-BuOOH gives either β-silyloxy-α,β-enones or α,β-enones in good yields depending on the base used.

Bronsted acid-promoted cyclizations of siloxyalkynes with arenes and alkenes

We have described the first Bronsted acid-mediated cyclizations of siloxyalkynes with simple arenes and alkenes to afford substituted tetralone and cyclohexenone derivatives. The most notable aspect of the carbocyclizations involving siloxyalkynes is the ability to employ a range of substrates that are not restricted to those containing electron-rich arenes and alkenes. The key mechanistic feature of the reaction is the generation of a highly reactive ketenium ion upon protonation of siloxyalkyne. We believe that the low nucleophilicty of the counteranion is crucial for enabling the formation and effective interception of this highly reactive intermediate. Copyright