Carbonyls, organometallic chemistry

A review concerning the coordination and organometallic chemistry of P- and As-carbonyl stabilized ylides was published in1998. The references quoted inside, being previous to the period concerned by our article, are not detailed here but they represent a very interesting basis to the results described below [66]. 

Cavell KJ, McGuinness DS (2007) Palladium complexes with carbonyl, isocyanide and carbene ligands. In Crabtree RH, Mingos DMP, Canty AJ (eds) Comprehensive organometallic chemistry 111. Elsevier, Amsterdam... 

Zhu, Z., Cameron, B.R. and Skerlj, R.T. (2003) Cycloauration of substituted 2-phenoxypyridine derivatives and X-ray crystal structure of gold, dichloro[2-[[5-[(cyclopentylamino)carbonyl]-2-pyridinyl- N]oxy]phenyl- C]-, (SP-4-3)-. Journal of Organometallic Chemistry, 677, 57. 

High-valent Co complexes incorporating carbonyl ligands are rare, and those extant are outside the scope of this review. The companion series Comprehensive Organometallic Chemistry covers this area. 

Dixon, K. R. Dixon, A. C. Palladium Complexes with Carbonyl, Isocyanide and Carbene Ligands, In Comprehensive Organometallic Chemistry II A review of the literature 1982-1994 Puddephatt, R. J. Ed., Elsevier, 1995, Vol. 9, p 193. 

In spite of the rich chemistry developed starting from the OsHCl(CO)(P Pr3)2 complex, the presence of a carbonyl group in its coordination sphere is probably a limitation for some subsequent developments. In this context it seems important to mention the encouraging reactivity of the related osmium(IV) complex, OsH2Cl2(P Pr3)2, that in methanol afford OsHCl(CO)(P Pr3)2. We believe that both interrelated osmium complexes present not only a rich chemistry but also a promising future as starting materials in organometallic chemistry. 

Until recently, fast time-resolved IR spectroscopy has been a technique fraught with difficulty. Generally it has been easier to use low temperature techniques, particularly matrix isolation (2,4), to prolong the lifetime of the fragments so that conventional spectrometers can be used. In the last 5 years, however, there have been major advances in fast IR spectroscopy. It is now posssible to detect metal carbonyl intermediates at room temperature in both solution and gas phase reactions. In Section II of this article, we explain the principles of these new IR techniques and describe the apparatus involved in some detail. In Section III we give a self-contained summary of the organometallic chemistry that has already been unravelled by time-resolved IR spectroscopy. 

The attack on coordinated carbon monoxide by nucleophiles was first extensively developed in synthetic organometallic chemistry by E. 0. Fischer and his students (6) as discussed by others in this volume, this reaction provides one route to the reduction of coordinated CO and to catalysis of the water gas shift reaction. Those carbonyl groups which are susceptible to attack by nucleophiles are electron deficient, as judged by their high CO stretcing frequencies (7). 

A. Lubineau, J. Auge, Y. Queneau, Carbonyl Additions and Organometallic Chemistry in Water in Organic Synthesis in Water (Ed. P. A. Grieco), Blacky Academic and Professional, London, 1998, pp.102-140. 

It is now nearly 40 years since the introduction by Monsanto of a rhodium-catalysed process for the production of acetic acid by carbonylation of methanol [1]. The so-called Monsanto process became the dominant method for manufacture of acetic acid and is one of the most successful examples of the commercial application of homogeneous catalysis. The rhodium-catalysed process was preceded by a cobalt-based system developed by BASF [2,3], which suffered from significantly lower selectivity and the necessity for much harsher conditions of temperature and pressure. Although the rhodium-catalysed system has much better activity and selectivity, the search has continued in recent years for new catalysts which improve efficiency even further. The strategies employed have involved either modifications to the rhodium-based system or the replacement of rhodium by another metal, in particular iridium. This chapter will describe some of the important recent advances in both rhodium- and iridium-catalysed methanol carbonylation. Particular emphasis will be placed on the fundamental organometallic chemistry and mechanistic understanding of these processes. 

Methanol carbonylation has been the subject of several reviews, including Denis Forster s seminal studies at Monsanto [4-10]. This chapter will not seek to repeat all the information included in those reviews but will focus on the role of organometallic chemistry in recent process development. 

A comparatively recent and extremely valuable extension of phase-transfer catalysis is to be found in its application to the chemistry of metal carbonyls, which crosses the boundaries of inorganic chemistry, through organometallic chemistry, and into organic chemistry. 

Oxidative addition to complex 1 is the slowest and rate-determining step in the reaction scheme and also it is a singular step, involving the conversion of the catalyst resting state to a more reactive 2. An obvious way to obtain a faster catalyst is the substitution of carbonyl ligands in 1 by electron-donating phosphines, as organometallic chemistry tells us this variation never fails. Indeed, several variants that are indeed fester are known [11], but none of them has found application. 

Activated mercaptans undergo desulfurization to hydrocarbons using cobalt carbonyl or triiron dodecacarbonyl as the metal complex, and basic phase transfer conditions (5 ). Acidic phase transfer catalysis has been little investigated, the first example in organometallic chemistry being reported in 1983 (reduction of diarylethylenes)( ). When acidic phase transfer conditions (sodium 4-dodecylcenzenesulfo-nate as the phase transfer catalyst) were used for the desulfurization of mercaptans [Fe3(CO)] 2 the metal complex],... 

Phase transfer catalysis has more recently been applied to the important area of organometallic chemistry(18). Reported applications include both the preparation(19) and the use of transition metal catalysts in isomerizations(20), carbonylations(21) and reductions(22). 

Haynes, A. (2005) Acetic acid synthesis by catalytic carbonylation of methanol, in Topics in Organometallic Chemistry, Vol. 18 (ed. M. Beller), Springer-Verlag, Berlin, pp. 179-205. 

Homs, N. and d. 1. Piscina, P.R. (2009) Carbonyl compounds as metallic presursors of tailored supported catalysts, in Modern Surface Organometallic Chemistry (eds J.M. Bassett, R. Psaro, D. Boberto and R. Ugo), Chapter 8, Wiley-VCH, Weinheim. 

Rhenium(0) compounds are rare and frequently lie in the realm of the organometallic chemistry. A simple example is decacarbonyldirhenium(0) in which two staggered, square-pyramidal Re(CO)5 fragments are held together by a single rhenium-rhenium bond. Substitution of carbonyl ligands is possible by tertiary phosphines and arsines, silanes and isocyanides, and binuclear Re-Re, Mn-Re, and Co-Re complexes have been studied. " Successive replacement of CO ligands can readily be observed by vibrational spectroscopy. This has been demonstrated... 

In this chapter, the recent advances in amidocarbonylations, cyclohydrocarbonylations, aminocarbonylations, cascade carbonylative cyclizations, carbonylative ring-expansion reactions, thiocarbonylations, and related reactions are reviewed and the scope and mechanisms of these reactions are discussed. It is clear that these carbonylation reactions play important roles in synthetic organic chemistry as well as organometallic chemistry. Some of the reactions have already been used in industrial processes and many others have high potential to become commercial processes in the future. The use of microwave irradiation and substitutes of carbon monoxide has made carbonylation processes suitable for combinatorial chemistry and laboratory syntheses without using carbon monoxide gas. The use of non-conventional reaction media such as SCCO2 and ionic liquids makes product separation and catalyst recovery/reuse easier. Thus, these processes can be operated in an environmentally friendly manner. Judging from the innovative developments in various carbonylations in the last decade, it is easy to anticipate that newer and creative advances will be made in the next decade in carbonylation reactions and processes. 

Carbon monoxide, a common ligand in organometallic chemistry, is known to insert into palladium-carbon bonds readily. This feature of the metal is frequently utilized when palladium catalyzed reactions are run in the presence of CO. The products of such reactions, also known as carbonylative couplings, incorporate a carbonyl group between the coupling partners. 

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