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Catalytic Bu4NOAc as silicon activator of ethyl 2-(trimethylsilyl) acetate, in THF, was utilized for the synthesis of β-hydroxy esters, whereas employing catalytic Bu4NOTMS gave α,β-unsaturated esters. The established reaction conditions were applicable to a diverse range of aromatic, heteroaromatic, aliphatic aldehydes and ketones. Reactions were achieved at room temperature without taking any of the specialized precautions that are in place for other organometallics. A stepwise olefination pathway via silylated β-hydroxy esters with subsequent elimination to form the α,β-unsaturated ester has been demonstrated. The key to selective product formation lies in use of the weaker acetate activator which suppresses subsequent elimination whereas stronger TMSO– activator (and base) facilitates both addition and elimination steps. The use of tetrabutyl ammonium salts for both acetate and trimethylsilyloxide activators provide enhanced silicon activation when compared to their inorganic cation counterparts. [ABSTRACT FROM AUTHOR]

In recent years organic chemistry has been impacted tremendously by the explosive growth of fashionable, innovative technologies, such as microwave flash heating, continuous micro/flow processes, polymer-supported reagents/catalysts, and so on. In the repertoire of high-throughput techniques, microwave-assisted heating is heavily used in academic laboratories and in industry. The use of continuous flow/microreactors is also no longer academic curiosity but is widely exploited in scale-up ('scale-out') for process intensification in the pharmaceutical as well as the fine chemical industries. Glycosylations via high-throughput strategies have remained underdeveloped, albeit over a period of nine decades, they have been successfully used to decorate bioactive nucleosides. The coupling between silanolate nucleophiles and the corresponding sugar partners in the presence of a Lewis acid is commonly referred to as the silyl Hilbert-Johnson reaction or Vorbrüggen glycosylation, which is considered one of the most frequently used methods of glycosylation. The aim of this Focus Review is to showcase the remarkable influence of 'superheating' generated by high-speed non-conventional heating devices, continuous flow/microreactors, or microwaves over classical thermal heating to accomplish efficient Vorbrüggen glycosylations for the resourceful collection of functionalized nucleosides. [ABSTRACT FROM AUTHOR]

The synthesis of bench-stable α,α-bis(trimethylsilyl)toluenes and tris(trimethylsilyl)methane is described and their use in stereoselective Peterson olefinations has been achieved with a wide substrate scope. Product stereoselectivity was poor with carbonyl electrophiles (E/Z ∼1:1 to 4:1) though this was significantly improved by employing the corresponding substituted N-benzylideneaniline (up to 99:1) as an alternative electrophile. The olefination byproduct was identified as N,N-bis(trimethylsilyl)aniline and could be easily separated from product by aqueous acid extraction. Evidence for an autocatalytic cycle has been obtained., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)