Asymmetric borylation of α,β-unsaturated esters catalyzed by novel ring expanded N-heterocyclic carbenes based on chiral 3,4-dihydro-quinazolinium compounds.
نویسندگان
چکیده
A series of chiral 6-membered ring N-heterocyclic carbene (NHC) precursors based on 3,4-dihydro-quinazoline were synthesized with overall yields of 54-62%. NHCs generated from these precursors show excellent asymmetric catalytic properties for borylation of α,β-unsaturated esters with enantioselectivity of up to 93% with a catalyst content of only 1 mol%.
منابع مشابه
Isoquinoline-based chiral monodentate N-heterocyclic carbenes.
C(1)-symmetric isoquinoline-based chiral diaminocarbene ligands (MIQ) have been developed to block three quadrants of the metal coordination sphere, complementing C(2)-symmetric biisoquinoline-based ligands (BIQ). MIQ-Cu complexes catalyzed conjugate borylation of various α,β-unsaturated amides in good yields (82-99%) and enantioselectivities (75-87% ee).
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ورودعنوان ژورنال:
- Organic & biomolecular chemistry
دوره 12 34 شماره
صفحات -
تاریخ انتشار 2014