1242310-34-4Relevant academic research and scientific papers
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.
, p. 9519 - 9522 (2017)
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.
Double diastereoselective, nucleophile-catalyzed aldol lactonizations (NCAL) leading to β-lactone fused carbocycles and extensions to β-lactone fused tetrahydrofurans
Morris, Kay A.,Arendt, Kevin M.,Oh, Seong Ho,Romo, Daniel
supporting information; experimental part, p. 3764 - 3767 (2010/11/04)
A double diastereoselective variant of the nucleophile-catalyzed aldol lactonization (NCAL) process is described. This strategy delivers β-lactone-fused carbocycles with good to excellent diastereoselectivities using cinchona alkaloid catalysts with enantioenriched aldehyde acids, which gave low diastereoselectivity based on substrate control alone. β-Lactone-fused tetrahydrofurans are also prepared for the first time via the NCAL process; however, diastereoselectivity was only modestly improved when applying double diastereodifferentiation to these systems.
