1073354-07-0Relevant articles and documents
Complex Boron-Containing Molecules through a 1,2-Metalate Rearrangement/anti-SN2′ Elimination/Cycloaddition Reaction Sequence
Tillin, Chloe,Bigler, Raphael,Calo-Lapido, Renata,Collins, Beatrice S.L.,Noble, Adam,Aggarwal, Varinder K.
, p. 449 - 453 (2019)
The three-component coupling of benzylamines, boronic esters, and 4-phenyl-3 H -1,2,4-triazole-3,5(4 H)-dione (PTAD) is reported. The boronate complex formed from an ortho -lithiated benzylamine and a boronic ester undergoes a stereospecific 1,2-metalate rearrangement/ anti -S N 2′ elimination in the presence of an N-activator to provide a dearomatized tertiary boronic ester. Interception of this dearomatized intermediate with a dienophile leads to stereopredictable cycloaddition reactions to generate highly complex three-dimensional boron-containing molecular structures. When enantioenriched α-methyl-substituted benzylamines are employed, the corresponding cycloaddition adducts are formed with excellent enantiospecificities.
Enantiospecific Synthesis of ortho-Substituted Benzylic Boronic Esters by a 1,2-Metalate Rearrangement/1,3-Borotropic Shift Sequence
Aichhorn, Stefan,Bigler, Raphael,Myers, Eddie L.,Aggarwal, Varinder K.
supporting information, p. 9519 - 9522 (2017/07/25)
Coupling reactions between benzylamines and boronic esters have been investigated. ortho-Lithiated benzylamines react with boronic esters and a N-activator to afford ortho-substituted benzylic boronic esters with formal 1,1′-benzylidene insertion into the C-B bond. The reaction occurs by a SN2′ elimination and 1,2-metalate rearrangement of the N-activated boronate complex to afford a dearomatized intermediate, which undergoes a Lewis-acid catalyzed 1,3-borotropic shift to afford the boronic ester products in high yield and with excellent enantiospecificity. The use of enantioenriched α-substituted benzylamines gave the corresponding secondary boronic esters with high ee.