Comparison of computational studies of internal stabilization of 1‐butadienyllithiums and representative 1‐chloro‐1‐lithio‐2‐phenylalkenes

Comparison of molecular orbital calculations of 1‐butadienyllithiums and representative 1‐chloro‐1‐lithio‐2‐phenylalkenes, carried out by using MNDO and AM1, reveals that the major stabilizing interaction with lithium in these systems is predicted to be agostic bonding between lithium and hydrogen. MNDO and AM1 calculations for 1‐chloro‐1‐lithio‐2‐phenylethenes give evidence for agostic bonding between lithium and the ortho H, such as compressed pertinent bond angles and increased pertinent bond lengths. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:263–269, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10027