146514-16-1Relevant articles and documents
Silylcuprate Routes to Cyclohex-2-enylsilanes
Laycock, Bronwyn,Maynard, Ian,Wickham, Geoffrey,Kitching, William
, p. 693 - 700 (1988)
The efficacy of the dimethyl(phenyl)silylcuprate and (to a lesser extent) the methyl-diphenylsilylcuprate reagents in converting cyclohex-2-enyl chlorides into the corresponding allylsilanes has been investigated.The presence of copper(I) greatly suppresses formation of the coupled hydrocarbon, and promotes stereo- and regio-selective carbon-silicon bond formation, in a predominantly anti-SN2' manner.Spectroscopic characterization of the diastereomeric silanes is presented.Grignard routes to some of these silanes are described.
Silicon Grignard Reagents as Nucleophiles in Transition-Metal-Catalyzed Allylic Substitution
Xue, Weichao,Oestreich, Martin
, p. 233 - 239 (2019/01/04)
A broad range of transition-metal catalysts is shown to promote allylic substitution reactions of allylic electrophiles with silicon Grignard reagents. The procedure was further elaborated for CuI as catalyst. The regioselectively is independent of the leaving group for primary allylic precursors, favoring α over γ. The stereochemical course of this allylic transposition was probed with a cyclic system, and anti -dia-stereoselectivity was obtained.
Practical synthesis of allylic silanes from allylic esters and carbamates by stereoselective copper-catalyzed allylic substitution reactions
Oestreich, Martin,Auer, Gertrud
, p. 637 - 640 (2007/10/03)
The first copper-catalyzed allylic substitution reactions of allylic acetates and carbamates employing a bis(triorganosilyl)zinc reagent are reported. This novel procedure avoids the use of stoichiometric amounts of copper salts which are usually mandatory with this chemistry. Application of this methodology to standard model substrates substantiates a high diastereoselectivity for the double bond geometry (E:Z) as well as the relative configuration (syn:anti).
A Regioselective and Stereospecific Synthesis of Allylsilanes from Secondary Allylic Alcohol Derivatives
Fleming, Ian,Higgins, Dick,Lawrence, Nicholas J.,Thomas, Andrew P.
, p. 3331 - 3350 (2007/10/02)
Primary and secondary allylic acetates and benzoates react with the dimethyl(phenyl)silyl-cuprate reagent to give allylsilanes, provided that the THF in which the cuprate is prepared is diluted with ether before addition of the allylic ester.The reaction is reasonably regioselective in some cases: (i) when the allylic system is more-substituted at one end than the other, as in the reactions 4->5 and 9->10; (ii) when the steric hindrance at one end is neopentyl-like, as in the reactions 15->16; and (iii) when the disubstituted double bond has the Z configuration, as in th e reactions Z-19->E-21 or, better, because the silyl group is becoming attached to the less-sterically hindered end of the allylic system, Z-20->E-22.The regioselectivity is better if a phenyl carbamate is used in place of the ester, and a three-step protocol assembling the mixed cuprate on the leaving group is used, as in the reactions 23->24 and E- or Z-29->E-21, or, best of all, because the silyl group is again becoming attached to the less-sterically hindered end of the allylic system, E- or Z-30->E-22.This sequence works well to move the silyl group onto the more substituted end of an allyl system, but only when the move is from a secondary allylic carbamate to a tertiary allylsilane, as in the reaction 38->39.Allyl(trimethyl)silanes can be made using alkyl- or aryl-cuprates on trimethylsilyl-containing allylic esters and carbamates, as in the reactions 40->41, and 43->44.The reaction of the silyl-cuprate with allylic esters and the three-step sequence with the allylic carbamates are stereochemically complementary, the former being stereospecifically anti and the latter stereospecifically syn.Homochiral allylsilanes can be ma de by these methods with high levels of stereospecificity, as shown by the synthesis of the allylsilanes 54, 58 and 59.
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
ALLYLSILANES FROM ALLYLCHLORIDES AND SILYLCUPRATES
Laycock, Bronwyn,Kitching, William,Wickham, Geoffrey
, p. 5785 - 5788 (2007/10/02)
The beneficial effects of copper (I) salts on the reactions of cyclohex-2-enyl chlorides and 3,4-epoxycyclohexene with phenyldimethylsilyllithium are reported.
