New synthesis of Fischer-type hydrazino(alkyl) complexes. First X-ray characterisation of a chelate hydrazino derivative

Formation of Metallacyclobutene Complexes via the Addition of Hydrazines to Ruthenium Vinylidene Complexes

“…The bond lengths and bond angles of the four-membered metallacycles of 1 , 3 , and 4 are almost identical with those found for chromium complexes containing the same motif, such as tetracarbonyl[( N -benzyl- N ′, N ′-dimethylhydrazinyl)methylcarbene]chromium(0) ( 5 , Chart ). , …”

“…The bond lengths and bond angles of the four-membered metallacycles of 1, 3, and 4 are almost identical with those found for chromium complexes containing the same motif, such as tetracarbonyl[(N-benzyl-N′,N′-dimethylhydrazinyl)methylcarbene]chromium(0) (5, Chart 1). 21,22 The average Ru(1)-C(1) bond length of 1, 3, and 4, 1.97 Å, is similar to those found in other complexes of ruthenium containing a RudCNRR′ group. 7,13,25,26 The N(1)-N(2) bond length of the hydrazine unit, 1.442(12)-1.438(3) Å, for 1, 3, and 4 is comparable to that found in both free and metal-bound hydrazines.…”

“…[13][14][15][16][17][18][19] The syntheses of complexes 1-4 are the first examples of the formation of such a metallacycle from the reaction of a hydrazine with a vinylidene ligand. The only other examples of metal complexes containing a -M-C-N-Nring were derived from a Nacetylhydrazine ligand bound to chromium [20][21][22] (e.g., 5) or the reaction between a diazene species and a rhenium carbyne complex 23 (e.g., 6) (Chart 1).…”

“…Metallacyclobutene complexes where one or more members of the four-membered ring is a heteroatom (such as oxygen, phosphorus, or nitrogen) are rare. − The syntheses of complexes 1 − 4 are the first examples of the formation of such a metallacycle from the reaction of a hydrazine with a vinylidene ligand. The only other examples of metal complexes containing a −M−C−N−N− ring were derived from a N -acetylhydrazine ligand bound to chromium − (e.g., 5 ) or the reaction between a diazene species and a rhenium carbyne complex (e.g., 6 ) (Chart ).…”

N‐Acylhydrazines: Future Perspectives Offered by New Syntheses and Chemistry

“…During some studies of hydrazinocarbene complexes, it has been found that these organometallics are good and efficient synthetic equivalents of their organic isolobal analogues 45, and can be used with high synthetic potential in carbon-carbon bond-forming reactions. In particular, the presence of the lone pair on the β-nitrogen atom means that the (Z)-pentacarbonyl complexes of type 44 can be quantitatively transformed into the stable chelate complexes 46, in which the β-nitrogen atom replaces one of the four cis CO ligands of the metal [39] (Scheme 13). Scheme 13 Moreover, hydrogen atoms located in the α-position with respect to the carbene carbon atom are acidic; these complexes can be efficiently deprotonated with strong bases, and the obtained anions react easily with various electrophiles.…”