%0 Generic
%A Wang, Xiao-Na
%A Krenske, Elizabeth H.
%A Johnston, Ryne C.
%A Houk, K. N.
%A Hsung, Richard P.
%D 2015
%T AlCl3‑Catalyzed Ring Expansion Cascades
of Bicyclic Cyclobutenamides Involving Highly Strained Cis,Trans-Cycloheptadienone Intermediates
%U https://acs.figshare.com/articles/dataset/AlCl_sub_3_sub_Catalyzed_Ring_Expansion_Cascades_of_Bicyclic_Cyclobutenamides_Involving_Highly_Strained_i_Cis_i_i_Trans_i_Cycloheptadienone_Intermediates/2172181
%R 10.1021/jacs.5b02561.s005
%2 https://ndownloader.figshare.com/files/3806107
%K AlCl
%K cyclobutenamide
%K ci
%K evidence
%K tetracyclic molecules
%K bicyclic
%K cascade reactions
%K electrocyclic ring opening
%K DFT calculations
%K Bicyclic Cyclobutenamides
%K ketone
%X We report the first experimental
evidence for the generation of
highly strained cis,trans-cycloheptadienones
by electrocyclic ring opening of 4,5-fused cyclobutenamides. In the
presence of AlCl3, the cyclobutenamides rearrange to [2.2.1]-bicyclic
ketones; DFT calculations provide evidence for a mechanism involving
torquoselective 4π-electrocyclic ring opening to a cis,trans-cycloheptadienone followed by a Nazarov-like
recyclization and a 1,2-alkyl shift. Similarly, 4,6-fused cyclobutenamides
undergo AlCl3-catalyzed rearrangements to [3.2.1]-bicyclic
ketones through cis,trans-cyclooctadienone
intermediates. The products can be further elaborated via facile cascade
reactions to give complex tri- and tetracyclic molecules.
%I ACS Publications