Enantio- and Diastereoselective Cyclopropanation of 1-Alkenylboronates: Synthesis of 1-Boryl-2,3-Disubstituted Cyclopropanes.
A novel, highly enantio- and diastereoselective synthesis of 1-boryl-2,3-disubstituted cyclopropanes has been developed by means of the cyclopropanation of alkenylboronates with ethyl diazoacetate in the presence of catalytic amounts of a chiral copper(I) complex. The products can also be directly accessed from alkynes through an operationally simple, sequential hydroboration-cyclopropanation protocol. The resulting enantioenriched 1-boryl-2,3-disubstituted cyclopropanes are versatile synthetic intermediates that undergo further transformations at the carbon-boron bond.
['Carreras|Javier|J|0000-0002-1521-6758', 'Caballero|Ana|A|0000-0001-7846-6183', 'Pérez|Pedro J|PJ|0000-0002-6899-4641']
cyclopropanes alkenylboronates asymmetric catalysis copper hydroboration