Isocyanide chemistry

While on the subject of reviews, attention should also be directed to a very recent collection of articles on isocyanide chemistry edited by Ugi 156). This volume is oriented somewhat toward the organic chemistry of isocyanides, but not with the complete exclusion of metal complexes of these species one is directed in particular to the chapters by Vogler (Chapter 10) on coordinated isocyanides and by Saegusa and Ito (Chapter 4) on a-additions to isocyanides. These latter reactions are often catalyzed by copper(I) compounds and occasionally by other metal complexes as well, and it is believed that this catalysis is accomplished by intermediate formation of metal isocyanide complexes. 

This proton transfer reaction is not fast, and it is suggested that this may be a more complicated reaction than was anticipated, perhaps occurring by initial addition of OH or OR to the metal followed by H2O or ROH expulsion. In support of this is the isolation of a complex Os(CO)-(CNC6H4CH3)(PPh3)2(H)OR from an analogous reaction sequence. (This is the only reference yet to any osmium carbonyl-isocyanide chemistry.)... 

The new era of isocyanide chemistry was determined by two aspects. First, it was the formation of products by MCRs with high numbers of educts and second, the recently initiated search for new desirable products in libraries of MCR... 

Marcaccini S, Pepino R, Cruz Pozo M (2001) A facile synthesis of 2, 5-diketopiperazines based on isocyanide chemistry. Tetrahedron Lett 42 2727-2728... 

Bruttomesso AC, Eiras J, Ramirez JA, Galagovsky LR (2009) Highly stereoselective synthesis of steroidal 2, 5-diketopiperazmes based on isocyanide chemistry. Tetrahedron Lett 50 4022 024... 

It is over eight years since the last comprehensive review appeared on metal isocyanide chemistry. In the interim, reviews have appeared on specific aspects of isocyanide chemistry. Lippard reviewed seven and eight coordination in molybdenum isocyanide compounds (7), Yamamoto reviewed metal(O)- isocyanide complexes (2), and in related reviews on car-bene complexes by Cotton and Lukehart (5), Lappert et al. (4), and Casey (5), mention was made of carbenes synthesized from metal isocyanides. 

This catalytic labilization of carbonyl groups has been extended to the replacement of carbonyls in metal carbonyl clusters. Metal cluster complexes are at present the subject of extensive studies, partly because of their possible relevance as models for chemisorbed metal surfaces and because of their catalytic activity. The majority of these clusters contain carbonyl ligands, and these have been prepared from the vast number of metal carbonyl precursors generally available by a variety of synthetic methods usually without recourse to designed or rational procedures. In metal isocyanide chemistry, however, suitable precursors are lacking, and as a consequence, there are few routes to homoleptic metal-isocyanide clusters, and few isocyanide clusters are known (see Section IV,A). 

Bossio, R., Marcos, C. F., Marcaccini, S., Pepino, R. A facile synthesis of 3-lactams based on the isocyanide chemistry. Tetrahedron Lett. 1997, 38, 2519-2520. 

An increasing number of different isocyanides was produced, such that 329 known isocyanides were described in Isonitrile Chemistry in 1971 [8]. By comparison, during the era of classical isocyanide chemistry before 1960, only about 12 isocyanides were known. 

In the past few years, many new chemical compounds have been made prepared by the MCRs of the isocyanides than by all other types of chemical reactions combined, as isocyanide chemistry - and especially one-pot MCR procedure - has far greater variability than does any other facet of synthetic chemistry. 

The realization that this was a new type of compound, isomeric to the nitriles, and the elaboration of the classical methods for the preparation of isocyanides, the alkylation method and the carbylamine method by Gautier and Hofmann, initiated an active period of isocyanide chemistry that ended by the turn of the century with Nef s investigations on the reactions of the formally divalent carbon atom in the isocyanides. - TTie discovery of the Passerini reaction in 1921 led to a brief renaissance of isocyanide chemistry. 

The reason why isocyanide chemistry did not attract more researchers in its first century was not the suspected toxicity, nor the vile smell of the volatile isocyanides, but rather it was the lack of accessi-... 

As a result of this convenient method of synthesizing isocyanides, their chemistry has flourished vigorously in the past 30 years. Isocyanides are no longer an exotic class of compounds they are now routinely used as reagents by organic chemists. The preparative methods based on a-metallated isocyanides and the Ugi reactionare amongst the most important contributions of modem isocyanide chemistry to organic synthesis. 

The unique versatility of isocyanide chemistry is manifested in the diversity of its reactions. 

Another example of a free radical driven reaction cascade is given by the following reaction sequence, which clearly demonstrates the versatility and originality of isocyanide chemistry. 

H.E. writes - Thirty years ago, I started my doctoral thesis with a preparation of 2-chloroethyl chloroformate from phosgene on a 600 g scale. My supervisor was Ivar Ugi, an expert in phosgene chemistry, and Ugi s tradition in this field has been continued, particularly in isocyanide chemistry. In 1986, I rediscovered tri-pho ene and realized its potential, in principal, as a substitute for phosgene in... 

L. El Kaim, L. Grimaud, in Isocyanide chemistry applications in synthesis and material science (V. Nenajdenko, Ed.). Wiley-VCH Verlag GmbH, Weinheim, Germany, 2012, pp. 159-194. Ugi and Passerini reactions with carboxylic acid surrogates. 

Luzyanin, K. V. Pombeiro, A. J. L. In Carbene Complexes Derived from Metal-Bound Isocyanides , Nenajdenko, V., Ed. Isocyanide Chemistry, Wiley-VCH Verlag GmbH Weinheim, 2012 Chapter 15, p 531. 

Wessjoharai LA, Neves Filho RAW, Rivera DG (2012) Multiple multicomponent reactions with isocyanides. In Isocyanide chemistry. Wiley-VCH, Weinheim, pp 233-262... 

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