The X-Ray and NMR Studies on the Regio- and Stereoselective Courses for Insertion of Ketones into the s-cis- and s-trans-Diene Complexes of Zirconium Leading to (Z)-1,2-Oxazirconacyclohept-4-enes

Abstract

Abstract The s-trans-diene coordination in (η5-C5Me5)2Zr(butadiene) and the s-cis-diene coordination in (η5-C5Me5)2Zr(isoprene) were confirmed by the 1H- and 13C-NMR spectral studies. The reaction of 2,4-dimethyl-3-pentanone with these complexes occurred regio- and stereoselectively to give (Remark: Graphics omitted.) (5: R=H, 6: R=Me). The X-ray crystal structure analysis of 5 and 6 revealed the (Z)-configuration with respect to the olefin part. Crystal data for 5: monoclinic, space group P21/n with Z=4, a=11.650(2), b=17.791(3), c=13.612(2) Å, β=92.20(2)°, R=0.111 for 4308 non-zero reflections. Crystal data for 6: monoclinic, space group P21/n with Z=4, a=10.279(3), b=30.177(4), c=9.955(2) Å, β=108.67(2), R=0.104 for 3526 non-zero reflections.