Titanium(IV) Halide Mediated Coupling of Alkoxides and Alkynes: An Efficient and Stereoselective Route to Trisubstituted (E)-Alkenyl Halides
Min-Liang Yao, Travis R. Quick, Zhongzhi Wu, Michael P. Quinn and George W. Kabalka*
*Departments of Chemistry and Radiology, The University of Tennessee, Knoxville, Tennessee 37996-1600, Email: kabalkautk.edu
M.-L. Yao, T. R. Quick, Z. Wu, M. P. Quinn, G. W. Kabalka, Org. Lett., 2009, 11, 2647-2649.
C-O bond cleavage of lithium alkoxides occurs readily at room temperature in the presence of titanium(IV) halides. Capture of the resultant carbocation by alkynes provides an efficient route to trisubstituted (E)-alkenyl halides with high stereoselectivity.
see article for more examples
Generation of Cations from Alkoxides: Allylation of Propargyl Alcohols
G. W. Kabalka, M.-L. Yao, S. Borella, J. Am. Chem. Soc., 2006, 128, 11320-11321.
benzylation, propargylation, alkenes, vinyl bromides, vinyl chlorides