622382-82-5Relevant academic research and scientific papers
Silylformylation - Fluoride-assisted aryl migration of acetylenic derivatives in a versatile approach to the synthesis of polyfunctionalised compounds
Aronica, Laura Antonella,Raffa, Patrizio,Valentini, Giulia,Caporusso, Anna Maria,Salvadori, Piero
, p. 1845 - 1851 (2007/10/03)
Polyfunctionalised aldehydes and dihydropyrans are prepared from easily available functionalised 1-alkynes through a two-step silylformylation/aryl migration sequence. The silylformylation process is performed under mild experimental conditions and affords the corresponding β-silylalkenals in high yields. The fluoride-promoted migration step occurs instantaneously with quantitative conversion. The chemo-, regio- and stereoselectivity can be modulated according to the nature and the position of the functional group on the acetylene precursors. When a good leaving group is present in the ω position of the aliphatic chain of the alkyne a cyclisation product is obtained, while α,β-unsaturated aldehydes are generated from propargylic tosylamides. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
Fluoride-Promoted Rearrangement of Organo Silicon Compounds: A New Synthesis of 2-(Arylmethyl)aldehydes from 1-Alkynes
Aronica, Laura Antonella,Raffa, Patrizio,Caporusso, Anna Maria,Salvadori, Piero
, p. 9292 - 9298 (2007/10/03)
A new approach to 2-(arylmethyl)aldehydes 4 based upon a 1,2-anionotropic rearrangement of an aryl group is presented. The synthetic sequence begins with a silylformylation reaction of terminal acetylenes 5 with aryl and heteroaryl silanes 6, followed by treatment of the products (Z)-1 with TBAF. The optimization of the experimental conditions of the fluoride-promoted step is described, together with the synthetic potentialities of the process. A plausible mechanism of the rearrangement reaction is reported that suggests the addition of the fluoride ion to the arylsilicon moiety of β-silylalkenals (Z)-1 and the consequent migration of the aryl group to the adjacent carbon atom. Both aryl and heteroaryl substituents can rearrange without any loss of configuration. Bromofunctionalized substrates undergo an intramolecular reaction that affords exclusively carbacyclobenzyl aldehydes, further enhancing the high synthetic value of this method.
