%0 Journal Article
%T Asymmetric Diels每Alder reaction with >C=P每 functionality of the 2-phosphaindolizine-灰1-P-aluminium(O-menthoxy) dichloride complex: experimental and theoretical results
%A Rajendra K. Jangid
%A Nidhi Sogani
%A Neelima Gupta
%A Raj K. Bansal
%J Beilstein Journal of Organic Chemistry
%D 2013
%I 
%R 10.3762/bjoc.9.40
%X The Diels每Alder reaction of the 2-phosphaindolizine-灰1-P-aluminium(O-menthoxy) dichloride complex with dimethylbutadiene was investigated experimentally and computationally. The >C=P每 functionality of the complex reacts with 2,3-dimethylbutadiene with complete diastereoselectivity to afford [2 + 4] cycloadducts. Calculation of the model substrate, 3-methoxycarbonyl-1-methyl-2-phosphaindolizine-P-aluminium(O-menthoxy) dichloride (7a), at the DFT (B3LYP/6-31+G*) level reveals that the O-menthoxy moiety blocks the Re face of the >C=P每 functionality, due to which the activation barrier of the Diels每Alder reaction of 7a with 1,3-butadiene, involving its attack from the Si face, is lower. It is found that in this case, the exo approach of the diene is slightly preferred over the endo approach.
%K aluminium(O-menthoxy) dichloride
%K asymmetric synthesis
%K >C=P每 functionality
%K DFT calculations Diels每Alder reaction
%U http://dx.doi.org/10.3762/bjoc.9.40