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Diastereoselective Cyclopropanation through Michael Addition‐Initiated Ring Closure between α,α‐Dibromoketones and α,β‐Unsaturated Fischer Carbene Complexes
Author(s) -
Tobrman Tomáš,
Krupička Martin,
Polák Peter,
Dvořáková Hana,
Čubiňák Marek,
Babor Martin,
Dvořák Dalimil
Publication year - 2020
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201901503
Subject(s) - cyclopropanation , chemistry , carbene , ceric ammonium nitrate , michael reaction , ring (chemistry) , closure (psychology) , yield (engineering) , medicinal chemistry , stereochemistry , organic chemistry , catalysis , materials science , economics , market economy , grafting , metallurgy , polymer
The diastereoselective synthesis of tetrasubstituted cyclopropanes is described. The two‐step procedure is based on the 3‐exo‐tet Michael addition‐initiated ring closure. In the first step, the enolates derived from α,α‐dibromoketones react with the α,β‐unsaturated Fischer alkoxycarbene complexes to obtain tetrasubstituted cyclopropanes, which are then treated with ceric‐ammonium nitrate to yield the final products. The methodology tolerates diverse functional groups, and high diastereoselectivity (dr ≥ 98:2) is observed in all cases.