[(R)-1,1'bi-2,2'-Naphthoxy]LnI(THF)(2) (Ln: Yb, Sm, La) 5 have been prepared by reaction of the bispotassium salt. of (R)-binaphthol with lanthanide triiodides, and characterized. They are active catalysts for Diels-Alder reactions although with low asymmetric inductions. The lanthanum iodo bisbinaphthoxide gives a slightly higher enantiomeric excess than the two other complexes. (C) 2003 Elsevier Science B.V. All rights reserved.