205 Journal of Organometallic Chemistry, 389 (1990) 205-217 Elsevier Sequoia S.A., Lausanne - Printed in The Netherlands JOM 20662 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Iron complexes of l,l’-bis(diphenylphosphino)ferrocene (BPPF) as efficient catalysts in the synthesis of carbamates. X-ray crystal structure of (BPPF) Fe( CO) 3 Tae-Jeong Kim l , Kee-Ha Kwon, Soon-Chul Kwon, Jin-Ook Baeg, Sang-Chul Shim *, Department of Industrial Chemistry, Kyungpook National University, Taegu, 702 - 701 (Korea) and Dong-Ho Lee Department of Polymer Engineering, Kyungpook National University, Taegu, 702-701 (Korea) (Received October 17th, 1989; in revised form December 17th. 1989) Abstract l,l’-Bis(diphenylphosphino)ferrocene (BPPF) reacts with a 5-10 molar excess of Fe(CO), to give three new iron complexes (q*-BPPF)Fe(CO), (l), ( nl-BPPF)Fe(CO), (2), and (p,$-BPPF)Fe,(CO), (3) with the product distribution depending upon reaction conditions. The structure of 1 has been determined. Crystals are mono- clinic, space group P2,/c, with a 9.708(l), b 16.195(2), c 19.869(5) A, /I 95.75(2)“, V 3108(l) A3, Z = 4, and Dcalc 1.49 g cmh3. The geometry around the central iron is a distorted trigonal bipyramid, with the two phosphorus atoms occupying axial and equatorial positions. All these compounds can catalyze efficiently the reaction of propargyl alcohol with secondary amines in the presence of CO, to provide corresponding carbamate esters. The yields of some carbamates are among the highest (- 65%) ever reported in the literature. Introduction The catalytic incorporation of carbon dioxide into organic compounds has been an attractive goal in recent years since a number of functionalized substrates may be formed with this inexpensive, stable, and nontoxic reagent [l-3]. An important example is the catalytic formation of carbamates by the reactions of carbon dioxide and amines with alkynes as represented by the reaction in equation 1. HC=CR’ + R,NH + CO, -+ H,C=C(R’)OC(=O)NR, (1) This reaction provides a unique advantage over other preparative methods which include the conventional multistep synthesis based on toxic phosgene [4] and 0022-328X/90/$03.50 0 1990 - Elsevier Sequoia S.A.