1,3-Dipolar cycloaddition to the iron-imine (Fe-N:C) fragment. 8. Formation of 1,4,3a,6a-tetrahydropyrrolo[3,2-b]pyrroles via double 1,3-dipolar cycloaddition of alkynes to Fe(CO)2(CNR)(.alpha.-diimine). Competition between isocyanide and CO insertion. Determination of cone angles of isocyanides

1,3-Dipolar cycloaddition to the FeSC fragment 20. Preparation and properties of carbonyliron complexes of di-thiooxamide. Reactivity of the mononuclear (di-thiooxamide)Fe(CO)3 towards dimethyl acetylenedicarboxylate

“…Cooling the pentane solution to − 30°C resulted in a voluminous precipitate of the excess free Et 4 -DTO ligand. Filtration gave a deep green-blue solution containing a mixture of the mononuclear complex Fe(CO) 3 (Et 4 -DTO) (7d) and the The co-ordination behaviour of several R 2 -and R 4 -DTO ligands to Mo(CO) 4 − n (PR 3 ) n has been studied by tom Dieck et al [18,19]. For n = 0, 1, they found that the DTO ligand acts as a relatively strong donor and for n=2, the R 2 -and R 4 -DTO ligand acts as good p-acceptor ligand.…”

“…In the case of ligands a -d, initially, the deep green or blue Fe(CO) 3 (DTO) complexes (7) are observed before they react further with [FeCO) 4 ] to three different types of Fe 2 (CO) 6 (DTO) complexes 8. The reactions of 7a and 7d with DMAD have been studied.…”

“…In the case of the reaction with ligands b and c, the initial deep green-blue Fe(CO) 3 (DTO) complexes 7b,c are formed in low stationary concentrations because they directly react further with [Fe(CO) 4 ] to form the dimeric Fe 2 (CO) 6 [R%N C(S) (S)C(H)N(H)R%] complexes 8b,c in high yield. The two sulfur atoms of the modified DTO ligand in complexes 8b,c are reduced to sulfido groups which are bridging between the two Fe(CO) 3 fragments (m 2 -S co-ordination), thus acting as a six-electron donor.…”

“…In the last decade, the reactions of the mononuclear M(CO) n (CNR) 3 − n (R-DAB) complexes (M= Fe, Ru; n= 0, 1, 3) [1][2][3][4][5][6][7][8] with the alkynes DMAD and MP have been studied extensively in our laboratory. These reactions have been shown to give some interesting highly functionalised coordinated heterocyclic ligands such as in complexes 4 and 5 (cf.…”

“…Fe 2 (CO) 9 [34] 1 has been prepared according to the published procedure. The ligands cyclo-DTO [35] (a), R 2 -DTO (b, c) [36] and Et 4 -DTO (d) [36] were prepared according to published procedures.…”