Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Zirconium(IV) complexes of 5, 10, 15, 20-tetraphenylporphyrin ((TPP)ZrX 2 ) catalyze highly regio- and stereo-selective ethylalumination of terminal alkynes with satisfactorily high turnover numbers. ... More than 99 % regioselectivities with satisfactorily high turnover numbers ...