Syntheses of gyroscope-like molecules via three-fold ring closing metatheses of bis(phosphine) complexes trans-LyM(P((CH2)nCHdouble bond; length as m-dashCH2)3)2, and extensions to bis(phosphite) complexes trans-Fe(CO)3(P(O(CH2)nCHdouble bond; length as m

The synthesis of trigonal bipyramidal, square planar, and octahedral bis(phosphine) complexes of the formula trans-LyM(P((CH2)nCHdouble bond; length as m-dashCH2)3)2, and their conversion to gyroscope-like molecules trans-Ly via three-fold intramolecular alkene metathesis/hydrogenation sequences, is reviewed. New data involving bis(phosphite) complexes are then described. Reactions of P(NMe2)3 and HO(CH2)nCHdouble bond; length as m-dashCH2 (n = a, 3; b, 4; c, 5; d, 6; e, 8; f, 9) afford the ligands P(O(CH2)nCHdouble bond; length as m-dashCH2)3 (26a–f, 79–96%). Reactions of 26a,b,e,f and Fe(BDA)(CO)3 (BDA = benzylideneacetone) give trans-Fe(CO)3(P(O(CH2)nCHdouble bond; length as m-dashCH2)3)2 (27a,b,e,f) as yellow or green oils in 17–64% yields after workup. Two representative complexes (27b,e) are treated with Grubbs’ catalyst (2 × 6.5 mol%). NMR analyses of the resulting crude trans-Fe(CO)3(P(O(CH2)nCHdouble bond; length as m-dashCH(CH2)nO)3P) (28b,e) suggest mixtures of Z/E isomers and perhaps oligomers. Subsequent ClRh(PPh3)3-catalyzed hydrogenations afford the title molecules trans (29b,e) as oils of 82–83% purity by 31P NMR. Although various properties of 29b,e can be compared to 27b,c, they could not be induced to solidify or crystallize, hampering purification.