54541-41-2Relevant articles and documents
Metalated nitriles: Internal 1,2-asymmetric induction
Fleming, Fraser F.,Liu, Wang,Ghosh, Somraj,Steward, Omar W.
, p. 7098 - 7100 (2007)
(Chemical Equation Presented) Steric screening: In alkylations of metalated nitriles containing vicinal methyl groups and a trisubstituted C=C bond, the butene moiety screens electrophilic attack from one diastereotopic face as the quaternary stereocenter
Regioselective carboindation of simple alkenes with indium tribromide and ketene silyl acetals
Nishimoto, Yoshihiro,Ueda, Hiroki,Inamoto, Yoshihiro,Yasuda, Makoto,Baba, Akio
supporting information; experimental part, p. 3390 - 3393 (2010/11/04)
(Equation Presented). The regioselective carboindation of simple alkenes with indium tribromide and ketene silyl acetals was accomplished. Various alkenes such as ethylene, 1-alkenes, and cyclic alkenes were applicable for this reaction system. The alkyli
Metalated nitriles: Internal 1,2-asymmetric induction
Fleming, Fraser F.,Liu, Wang,Ghosh, Somraj,Steward, Omar W.
, p. 2803 - 2810 (2008/09/19)
(Chemical Equation Presented) Alkylations of conformationally constrained acyclic nitriles containing vicinal dimethyl groups and an adjacent phenyl group or trisubstituted alkene are exceptionally diastereoselective. Probing the alkylation stereoselectivity with a series of C- and N-metalated nitriles implicates a reactive conformation in which an sp2-hybridized substituent projects over the metalated nitrile to avoid allylic strain. Steric screening thereby directs the electrophilic attack to the face of the metalated nitrile opposite the projecting substituent. Excellent stereoselectively is maintained in a diverse range of alkylations that efficiently install quaternary centers, even with isopropyliodide in which a contiguous array of tertiary-quaternary-tertiary stereocenters is created! Screening the conformational requirements with a series of acyclic nitriles and esters reveals the key structural requirements for high selectivity while providing a robust, predictive model that accounts for comparable ester alkylations affording the opposite diastereomer! The intensive survey of metalated nitrile alkylations identifies the key structural features required for high 1,2-asymmetric induction, addresses the long-standing challenge of asymmetric alkylations with acylic metalated nitriles, and provides a versatile method for installing hindered quaternary centers with excellent stereocontrol.
