%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/2172184 %R 10.1021/jacs.5b02561.s006 %2 https://ndownloader.figshare.com/files/3806110 %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