Carbonyl chemistry

LiAlH4, a strong reducing agent, reduces an acid chloride to a 1 alcohol. 

With LiAlH[OC(CH3)3]3, a milder reducing agent, reduction stops at the aldehyde stage. 

Tollens reagent (Ag20 + NH4OH) oxidizes RCHO only. Primary (1°) and secondary (2°) alcohols do not react with Tollens reagent. 

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The Eastman acetic anhydride [108-24-7] process provides an extension of carbonylation chemistry to carboxyUc acid esters. The process is based on technology developed independendy in the 1970s by Eastman and Halcon SD. The Eastman acetic anhydride process involves carbonylation of methyl acetate [79-20-9] produced from coal-derived methanol and acetic acid [64-19-7]. 

The quiaones have excellent redox properties and are thus important oxidants ia laboratory and biological synthons. The presence of an extensive array of conjugated systems, especially the a,P-unsaturated ketone arrangement, allows the quiaones to participate ia a variety of reactioas. Characteristics of quiaoae reactioas iaclude nucleophilic substitutioa electrophilic, radical, and cycloaddition reactions photochemistry and normal and unusual carbonyl chemistry. 

The first three chapters discuss fundamental bonding theory, stereochemistry, and conformation, respectively. Chapter 4 discusses the means of study and description of reaction mechanisms. Chapter 9 focuses on aromaticity and aromatic stabilization and can be used at an earlier stage of a course if an instructor desires to do so. The other chapters discuss specific mechanistic types, including nucleophilic substitution, polar additions and eliminations, carbon acids and enolates, carbonyl chemistry, aromatic substitution, concerted reactions, free-radical reactions, and photochemistry. 

I An overview chapter, A Preview of Carbonyl Chemistry, follows Chapter 18 and highlights the author s belief that studying organic chemistry requires both summarizing and Looking ahead. 

Carbonyl chemistry provides the most common anionic transition-metal compounds. 

There is only one substituent on the furan so it i 11 probably be best to disconnect within the side chain and come back to an intact furan as starting material. The side chain contains 1,3 1,4 and 1,6 relationships but the C-0 disconnection (39a) is particularly helpful. Important as carbonyl chemistry is, it is also important to look at other possible disconnections. lysis 1... 

The difference between carbonyl chemistry and (simple) carbocation chemistry is a result of much greater stability of the carbonyl group relative to a simple carbenium... 

Thns carbonyl chemistry can be considered as analogons to S l chemistry and is in fact inherently faster than 8 2 chemistry (not that 8 2 reactions cannot be fast, but this requires a strong thermodynamic driving force for a comparable driving force the carbonyl reaction is faster). 

Small Co metal clusters Cora (ra = 2-8) react with CO, with sequential addition leading to the saturated Co species [Co2(CO)7], [Co3(CO)i0], [Co4(CO)i2], [Co5(CO)13] and [Co6(CO)i5]-.71 This points towards one of the features of low-valent Co carbonyls a tendency to form stable clusters. Reactivity of Co with 02 is higher but leads to cluster fragmentation, whereas N2 is essentially unreactive. Entry into carbonyl chemistry of low-valent Co is frequently via the well-known dimer Co2(CO)8. A range of reactions commencing with this compound has been developed, as follows. 

While the replacement of carbon monoxide by a tertiary phosphine ligand represents one of the most fundamental substitution reactions in metal carbonyl chemistry, it was not until 1975, some 16 years after the... 

No specific recommendations can be given about the optimum reaction time. As speeding up reactions is a key motive for employing microwave irradiation, the reaction should be expected to reach completion within a few minutes. On the other hand, a reaction should be run until full conversion of the substrates is achieved. In general, if a microwave reaction under sealed-vessel conditions is not completed within 60 min then it needs further reviewing of the reaction conditions (solvent, catalyst, molar ratios). The reported record for the longest microwave-mediated reaction is 22 h for a copper-catalyzed N-arylation (see Scheme 6.63). The shortest ever published microwave reaction requires a microwave pulse of 6 s to reach completion (ultra-fast carbonylation chemistry see Scheme 6.49). 

Protonation of the carbonyl oxygen is as yet only recognized in a couple of cases (34,35). Even though O-alkylation and perhaps 0-protonation open up useful synthetic paths in metal carbonyl chemistry, their main interest for the purposes of this survey is their intermediacy in the further reduction of CO. 

The purpose of this article is to review recent results on the carbonylation chemistry of actinide-to-carbon sigma bonds, bearing in mind the unique properties of 5f-organometallics cited above. We focus our attention on the properties of bis(pentamethylcyclopentadienyl) actinide acyls. Just as transition metal acyls (A) occupy a pivotal role in classical carbonylation chemistry, it will be seen that many of the unusual... 

Dyson, P.J., Mclndoe, J.S. (Eds.), Transition Metal Carbonyl Chemistry. Gordon and Breach Amsterdam, 2000. 

Library of Congress Cataloging in Publication Data. Main entry under title Inorganic chemistry. Metal carbonyl chemistry. (Topics in current chemistry 71) 1. Metal carbonyls—Addresses, essays, lectures. I. Series. 

It is not intended to discuss the details of the various methods of thermochemical measurement and the evaluation of results. This has been done in authoritative articles by Skinner1 and by Pilcher2) which have appeared recently, and which deal specifically with the thermochemistry of organometallic compounds. Instead this article will survey the results which may be derived from the information which is available and relate them to features of metal carbonyl chemistry in particular. 

Otera J (ed) (2000) Modern Carbonyl Chemistry. Wiley, Weinheim... 

The ring-expansion carbonylation of epoxides is the most widely studied field in the epoxide carbonylation chemistry since the product lactones are highly attractive targets particularly, /1-lactones are useful compounds due to their versatility in organic synthesis [ 14,15] as well as their utilization as monomers to produce poly(3-hydroxyalkanoate)s, naturally occurring biodegradable polyesters [16-19]. 

Figure 15.8 a simple example is presented of a subsequent insertion of CO and methanolysis of the palladium acyl intermediate [14], This is not a very common reaction, because both the ligand requirements and the redox conditions for Wacker and carbonylation chemistry are not compatible. For insertion reactions one would use cis coordinating diphosphines or diimines, which makes the palladium centre more electron-rich and thus the nucleophilic attack in the Wacker part of the scheme will be slowed down. In addition, the oxidants present may lead to catalytic oxidation of carbon monoxide. 

The first application of phase transfer catalysis in metal carbonyl chemistry was reported by Alper in 1977(23). It was found that metal carbonyl anions could be readily generated by this technique and used to prepare pi-allyl, cluster, and ortho-metalated complexes(24). 

Another route that has been used recently to prepare Ft bimetal-lies (FtRu, i PtNi, and PtCr ) is via metal carbonyl chemistry. In this method, metal carbonyl complexes (either preformed or formed in situ)... 

The main theme to be appreciated here is that nucleophilic attack onto the nitrile triple bond can be interpreted mechanistically by extrapolation from carbonyl chemistry. 

It is worthwhile here to relate the behaviour of 2-chloropyridine and 2-methylpyridine to carbonyl chemistry. If we consider the pyridine ring as an imine, and therefore a carbonyl analogue (see Section 7.7.1), then with 2-chloropyridine we are... 

P. Perlmutter, Conjugate Addition Reactions in Organic Synthesis, Tetrahedron Organic Chemistry Series Vol. 9, Pergamon Press, Oxford, 1992 B. E. Rossiter and N. M. Swingle, Chem. Rev., 92, 111 (1992) J. Leonard, E. Dtez-Barra and S. Merino, Ear. J. Org. Chem., 2051 (1998) M. P. Sibi and S. Manyem, Tetrahedron, 56, 8033 (2000) N. Krause and A. Hoffmann-Roder, Synthesis, 171 (2001) K. Tomioka and Y. Nagaoka, in Comprehensive Asymmetric Catalysis (Eds. E. N. Jacobsen, A. Pfaltz and H. Yamamoto), Vol. Ill, Chap. 31.1, Springer, Berlin, 1999 K. Tomioka, in Modem Carbonyl Chemistry (Ed. J. Otera), Chap. 12, Wiley-VCH, Weinheim, 2000. 

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