97946-11-7Relevant academic research and scientific papers
Stereoselective synthesis of (Z)- and (E)-allylic silanes by copper- mediated substitution reactions of allylic carbamates with grignard reagents
Smitrovich, Jacqueline H.,Woerpel
, p. 1601 - 1614 (2007/10/03)
Both (Z)- and (E)-allylic silanes were prepared with high stereoselectivity by the copper-mediated substitution of allylic carbamates by organometallic reagents. The reaction of alkylmagnesium reagents with (E)- allylic carbamates provides (Z)-allylic silanes, whereas both alkylmagnesium and alkyllithium reagents react with (Z)-allylic carbamates to afford (E)- allylic silanes. Because Grignard reagents are often more facile to prepare than alkyllithium species, these reagents are the optimal nucleophiles for the synthesis of both (Z)- and (E)-allylic silanes. This method also allows readily available nonracemic allylic carbamates to be converted to chiral, nonracemic (Z)- and (E)-allylic silanes with high stereoselectivity.
A Regiocontrolled and Stereocontrolled Synthesis of Allylsilanes from β-Silyl Enolates
Fleming, Ian,Gil, Salvador,Sarkar, Achintya K.,Schmidlin, Tibur
, p. 3351 - 3362 (2007/10/02)
The α-lithiated diphenylphosphine oxides 3 react with methyl iodide to give the phosphine oxides 4 and 5 in a ratio 3-4:1.The corresponding reaction with aldehydes gives all four diastereomeric alcohols 7-10, which are not suitable for the synthesis of allylsilanes by a Wittig-Horner reaction.The β-dimethyl(phenyl)silyl enolates 13-15 and 25-28 react with aldehydes to give aldol products with high diastereoselectivity.The benzyl and allyl ester groups can be cleaved from these aldols to give the acids 16-18 and 29-32.The acids, in turn, can be induced to undergo dec arboxylative elimination stereospecifically either in a syn or an anti sense to give the allylsilanes 19, 20, 23, 24, 33, 34 and 39-41.A similar series of reactions can be carried out with the β-trimethylsilyl enolates 45 and 46 giving the allylsilanes 49, 50, 53 and 54.
Diastereoselective Aldol Reactions of β-Silylenolates: A New Regiocontrolled Synthesis of Allylsilanes
Fleming, Ian,Sarkar, Achintya K.
, p. 1199 - 1201 (2007/10/02)
Allylsilanes are prepared stereospecifically trans (10) or cis (12) and with complete regiocontrol by decarboxylative elimination of the β-hydroxy acids (9).
A Stereospecific Synthesis of Optically Active Allylsilanes
Fleming, Ian,Thomas, Andrew P.
, p. 1456 - 1457 (2007/10/02)
The phenyldimethylsilyl-cuprate reagent reacts with secondary allyl acetates stereospecifically anti, and with secondary and tertiary allyl urethanes stereospecifically syn; these reactions can be used to synthesise either enantiomer of an optically activ
Regiocontrolled Allylsilane Synthesis from Secondary Allylic Alcohol Derivatives
Fleming, Ian,Thomas, Andrew P.
, p. 411 - 413 (2007/10/02)
Unsymmetrical secondary allylic acetates and urethanes react with the dimethyl(phenyl)silylcuprate reagent to give allylsilanes with fair to good regioselectivity.
