JOURNAL OF ORGANOMETALLIC CHEMISTRY VOLUME 457, NUMBERS 1-2, SEPTEMBER 21, 1993 Contents Annual Surveys Boron: boranes in organic synthesis. Annual Survey covering the year 1989 G.W. Kabalka and L.H.M. Guindi (Knoxville, TN, USA) (Rec’d July 30, 1992) Boron: boranes in organic synthesis. Annual survey covering the year 1990 G.W. Kabalka and R.C. Marks (Knoxville, TN, USA) (Rec’d January 8, 1993) Lanthanides and actinides. Annual survey covering the year 1991 R.D. Rogers and L.M. Rogers (DeKalb, IL, USA) (Rec’d November 17, 1992) Organoiron chemistry. Annual survey for the year 1991 R.C. Kerber (Stony Brook, Long Island, NY, USA) (Rec’d September 30, 1992) Annual survey of ruthenium and osmium for the year 1990 M.G. Richmond (Denton, TX, USA) (Rec’d September 1, 1992) Transition metals in organic synthesis. Annual Survey covering the year 1991 L.S. Hegedus (Fort Collins, CO, USA) (Rec’d August 10, 1992) Transition metals in organic synthesis: hydroformylation, reduction, and oxidation. Annual Survey covering the year 1991 F. Ungvary (Veszprém, Hungary) (Rec’d June 30, 1992)