Titanium(IV) isopropoxide-catalysed reaction of alkylmagnesium halides with ethyl acetate in the presence of styrene. Non-hydride mechanism of ligand exchange in the titanacyclopropanes
作者:Oleg L. Epstein、Andrei I. Savchenko、Oleg G. Kulinkovich
DOI:10.1016/s0040-4039(99)01177-6
日期:1999.8
the preparation of3 by this method. The use of (CD3)2CHMgBr for the generation of the titanacyclopropane intermediates led to the formation of3. This result disagreed with the hydride mechanism of the ligand exchange for 2-phenyltitanacyclopropane (4) formation.
Iron catalyzed tandem ring opening/1,6-conjugate addition of cyclopropanols with <i>p</i>-quinone methides: new access to γ,γ-diaryl ketones
作者:Sachin R. Shirsath、Sagar M. Chandgude、M. Muthukrishnan
DOI:10.1039/d1cc05997a
日期:——
An iron(III) catalyzed tandem ring opening/1,6-conjugate addition of cyclopropanols to p-quinone methides leading to γ,γ-diaryl ketones has been described. This catalytic protocol provides a novel and efficient method to access γ,γ-diaryl ketone derivatives in good to excellent yields with high functional group tolerance. Importantly, γ,γ-diaryl ketone can be further functionalized to give a versatile
Divergent ring-opening coupling between cyclopropanols and alkynes under cobalt catalysis
作者:Junfeng Yang、Yixiao Shen、Yang Jie Lim、Naohiko Yoshikai
DOI:10.1039/c8sc02074d
日期:——
promote ring-opening coupling reactions between cyclopropanols and unactivated internal alkynes, affording either β-alkenyl ketones or multisubstituted cyclopentenol derivatives in good yields with good to excellent regioselectivities. The chemoselectivity between these β-alkenylation and [3 + 2] annulation reactions, which likely share a cobalt homoenolate as a key catalytic intermediate, is exquisitely
A number of aliphatic and arylaliphatic α,β-epoxy ketones were prepared in good yields in a one-pot procedure by a manganese-catalyzed ring cleavage of 1-substituted and 1,2-disubstituted cyclopropanols with oxygen followed by dehydration of the resulting cyclic peroxides with alkali.