Carbonyl compounds acyl halides

R2C=0, nitriles, a,p-unsaturated carbonyl compounds, acyl halides,... 

Insertion processes are reversible in certain cases, subject to thermodynamic factors in Eq. 7.1. Particularly important among the deinsertion processes is the decarbonylation by which a compound with one less carbon unit is produced. De-carbonylation of acyl halides and aldehydes are utilized for removing a carbonyl... 

Various organotin reagents react with acyl and aroyl halides under mild conditions without decarbonylation to give carbonyl compounds[390,39l]. Alkyl- or alkenyltin reagents react with acyl and aroyl chlorides to give ketones[548.733,734]. One example is the preparation of the a,/3-dnsaturated 7-keto esters 860 and 861, carried out under a CO atmosphere[735]. The reaction has been applied intramolecularly to the synthesis of the macrocyclic keto... 

Addition to Carbonyl Compounds. Unlike Grignard and alkykitliium compounds, trialkylboranes are inert to carbonyl compounds. The air-catalyzed addition to formaldehyde is exceptional (373). Alkylborates are more reactive and can transfer alkyl groups to acyl halides. The reaction provides a highly chemoselective method for the synthesis of ketones (374). 

Iron-acyl enolates such as 1, 2, and 3 react readily with electrophiles such as alkyl halides and carbonyl compounds (see Houben-Weyl, Vol. 13/9a p418). The reactions of these enolatc species with alkyl halides and similar electrophiles are discussed in Section D.1.1.1.3.4.1.3. To date, only the simple enolates prepared by a-deprotonation of acetyl and propanoyl complexes have been reacted with ketones or aldehydes. 

Similar additions have been successfully carried out with carboxylic acids, anhydrides, acyl halides, carboxylic esters, nitriles, and other types of compounds. These reactions are not successful when the alkene contains electron-withdrawing groups such as halo or carbonyl groups. A free-radical initiator is required, usually peroxides or UV light. The mechanism is illustrated for aldehydes but is similar for the other compounds ... 

Alkyltriphenylphosphonium halides are only weakly acidic, and a strong base must be used for deprotonation. Possibilities include organolithium reagents, the anion of dimethyl sulfoxide, and amide ion or substituted amide anions, such as LDA or NaHMDS. The ylides are not normally isolated, so the reaction is carried out either with the carbonyl compound present or with it added immediately after ylide formation. Ylides with nonpolar substituents, e.g., R = H, alkyl, aryl, are quite reactive toward both ketones and aldehydes. Ylides having an a-EWG substituent, such as alkoxycarbonyl or acyl, are less reactive and are called stabilized ylides. 

Organopalladium intermediates are also involved in the synthesis of ketones and other carbonyl compounds. These reactions involve acylpalladium intermediates, which can be made from acyl halides or by reaction of an organopalladium species with carbon monoxide. A second organic group, usually arising from any organometallic reagent, can then form a ketone. Alternatively, the acylpalladium intermediate may react with nucleophilic solvents such as alcohols to form esters. 

Sulfur compounds are useful as nucleophilic acyl equivalents. The most common reagents of this type are 1,3-dithianes, which on lithiation provide a nucleophilic acyl equivalent. In dithianes an umpolung is achieved on the basis of the carbanion-stabilizing ability of the sulfur substituents. The lithio derivative is a reactive nucleophile toward alkyl halides and carbonyl compounds. 11... 

Oxopropanedinitrile (Carbonyl dicyanide) [1115-12-4] 0 C(CN)2 Water Martin, E. L., Org. Synth., 1971, 51, 70 The nitrile reacts explosively with water. See related ACYL HALIDES See other CYANO COMPOUNDS c3n2o... 

Dehalogenation.1 DMBI effects dehalogenation of a-halo carbonyl compounds in a variety of ethereal solvents with formation of DMBI+X in generally high yield. The order of relative reactivity is Br > Cl > F (halides) and primary > secondary > tertiary (for the a-substituted position). In combination with HO Ac (1 equiv.) the reagent also reduces acyl chlorides to aldehydes (70-90% yield). 

While a large number of studies have been reported for conjugate addition and Sn2 alkylation reactions, the mechanisms of many important organocopper-promoted reactions have not been discussed. These include substitution on sp carbons, acylation with acyl halides [168], additions to carbonyl compounds, oxidative couplings [169], nucleophilic opening of electrophilic cyclopropanes [170], and the Kocienski reaction [171]. The chemistry of organocopper(II) species has rarely been studied experimentally [172-174], nor theoretically, save for some trapping experiments on the reaction of alkyl radicals with Cu(I) species in aqueous solution [175]. 

Acyl halides and anhydrides are important reactants for the formation of other carbonyl compounds, but you don t need to take up valuable brain space with information about any other acyl halide or anhydride reactions at this time. 

Organic carbonyl compounds—aldehydes, ketones, amides, and acyl halides—in which the carbonyl group is not part of a cyclic structure have interesting conformational properties that may differ widely according to the molecular system bearing these substituents. 

Enol Ethers and Esters 0-15 O-Alkylation of carbonyl compounds with diazo alkanes 0-17 Transetherification 0-20 Reaction between acyl halides and active hydrogen compounds 0-23 Transesterification 0-24 Acylation of vinylic halides 0-94 Alkylation with ortho esters 0-107 O-Acylation of 1,3-dicarbonyl compounds... 

Reaction of halo ketones or diazo ketones with boranes 0-102 Carbonylation of alkyl halides 0-104 Reaction between acyl halides and organometallic compounds 0-105 Reaction between other acid derivatives and organometallic compounds... 

Acetylenic carbonyl compounds Di-/x-carbonylhexacarbonyldicobalt, 99 Tributyltin chloride, 315 Acyl halides Acyl fluorides... 

Rh(CO)2 2(Por) complexes undergo addition reactions with carbonyl compounds and with alkyl halides to give acyl or alkyl Rhul(Por) similar to Rh1(CO)(phosphine)3 (Scheme 33).1.34... 

Carbonyl compounds will be taken in this chapter to mean any organic compound that contains at least one carbon-oxygen double bond where we limit the substitution to only saturated aliphatic, saturated alicyclic and aryl hydrocarbyl groups. Carbonyl compounds with a variety of unsaturated substituents have earlier been discussed within the context of enones4. Non-hydrocarbyl substituents, X , may be directly attached to the carbonyl and elsewhere in the molecule. The first type of species, RCOX, is alternatively identified as acyl derivatives such as carboxylic acids and their esters, halides and amides and have already been discussed in a recent Patai thermochemistry... 

A similar catalytic procedure for enantioselective formation of C-Br and C-Cl bonds has been reported recently by the Lectka group [83]. The concept of this a-halogenation of carbonyl compounds is tandem asymmetric halogenation and esterification (Scheme 3.28). Inexpensive acyl halides, 74, are used as starting... 

---