Heterocycle metalation

Ru(CO)3(GeMe)3]3 0.072 Triangle of Ru atoms form part of first established six-membered heterocyclic metal ring system. i... 

The reaction of heterocyclic lithium derivatives with organic halides to form a C-C bond has been discussed in Section 3.3.3.8.2. This cannot, however, be extended to aryl, alkenyl or heteroaryl halides in which the halogen is attached to an sp2 carbon. Such cross-coupling can be successfully achieved by nickel or palladium-catalyzed reaction of the unsaturated organohalide with a suitable heterocyclic metal derivative. The metal is usually zinc, magnesium, boron or tin occasionally lithium, mercury, copper, and silicon derivatives of thiophene have also found application in such reactions. In addition to this type, the Pd-catalyzed reaction of halogenated heterocycles with suitable alkenes and alkynes, usually referred to as the Heck reaction, is also discussed in this section. 

A combination of a ir-homocyclic or 77-heterocyclic metal moiety, a carbonylmetal fragment (CO) M, and an electron-poor boron heterocycle should lead to unsymmetrical triple-decker complexes. The first example (72) was reported by Grimes and co-workers (91), obtained from the reaction of [ (CH3—C BJIJjFeFy with [(C5H5)Co(CO)2] under UV... 

Friedheim EAH (1953) Heterocyclic metal and sulfur organic compounds. US Patent 2,664,432... 

Comenic acid, bromination, 58, 297 Complex induced proximity effect, in heterocyclic metalations, 56, 160 Complexes, charge transfer tetraphenyl-4,4 -bithiopyranylidene with lj +, -,60, 78,91... 

Over the last 15 years, the homogeneous studies of HDS and HDN processes have been extremely useful to understand many mechanistic details regarding the coordination of sulfur and nitrogen heterocycles to metal centers, hydrogen transfer from metal to coordinated heterocycle, metal insertion into C-S and C-N bonds, and the desulfurization/denitrogenation paths. Recently, however, there has been a qualitative leap in molecular catalysis so that crossing the border-... 

A variety of N-heterocyclic metal carbenes, although mostly known for their use in catalysis, are currently being investigated for new and exciting roles in medicine. Many of these NHC-metal complexes have shown the ability to treat multi-drug resistant infections and cancers for which there are currently no effective therapies. Although this is only a relatively small research area in... 

---