1108740-07-3Relevant articles and documents
Stereospecific Synthesis of Alkenes by Eliminative Cross-Coupling of Enantioenriched sp3-Hybridized Carbenoids
Wu, Zhenhua,Sun, Xun,Potter, Kristin,Cao, Yang,Zakharov, Lev N.,Blakemore, Paul R.
, p. 12285 - 12289 (2016)
1-Aryl-1,2-dialkylethenes were generated by a sequence of electrophilic substitution, 1,2-metalate rearrangement, and β-elimination initiated by the addition of enantioenriched α-(carbamoyloxy)alkylboronates to enantioenriched lithiated carbamates. The carbenoid stereochemical pairing [i.e., “like”=(S)+(S) or “unlike”=(S)+(R)] and the elimination mechanism (syn or anti), not substituent effects, determined the configuration of the trisubstituted alkene target. For example, (Z)-2,5-diphenyl-2-pentene was produced in 70 % yield with E/Z=5:95 by a like combination of Li and B carbenoids and syn (thermal) elimination whereas the E isomer was obtained in the same yield with E/Z>98:2 by an otherwise identical process involving an unlike stereochemical pairing. The concept elaborated overcomes an intrinsic limitation of traditional strategies for direct connective alkene synthesis, which cannot realize meaningful stereochemical bias unless the alkene substituents are strongly differentiated.
Stereospecific conversion of alcohols into pinacol boronic esters using lithiation-borylation methodology with pinacolborane
Roesner, Stefan,Brown, Christopher A.,Mohiti, Maziar,Pulis, Alexander P.,Rasappan, Ramesh,Blair, Daniel J.,Essafi, Stéphanie,Leonori, Daniele,Aggarwal, Varinder K.
supporting information, p. 4053 - 4055 (2014/04/03)
The synthesis of primary and secondary pinacol boronic esters via lithiation-borylation of carbamates and benzoates with pinacolborane is described. This new protocol enables the highly selective synthesis of enantioenriched and geometrically defined boronic esters that cannot otherwise be accessed by alternative methodologies. This journal is the Partner Organisations 2014.
