Metalated nitriles: chelation-controlled cyclizations to cis and trans hydrindanes and decalins.
Chelation provides a powerful means of stereocontrol in alkylations of metalated nitriles. Doubly deprotonating a series of cyclic beta-hydroxynitriles triggers cyclizations that implicate metalated nitrile intermediates having configurations imposed by chelation with an adjacent, chiral lithium alkoxide. Identifying chelation as a general stereocontrol element explains several previously anomalous alkylations of metalated nitriles and provides a potential solution to the long-standing difficulty of synthesizing trans-hydrindanes. Employing chelation to control the metalated nitrile geometry permits selective cyclizations to cis and trans hydrindanes and decalins and provides key insight into the geometrical requirements of these demanding cyclizations.
Fleming
Fraser F
FF
Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA. flemingf@duq.edu
Vu
Viet Anh
VA
Shook
Brian C
BC
Rahman
Moshfiqur
M
Steward
Omar W
OW