Aldehydes acid chloride

The at complex from DIB AH and butyllithium is a selective reducing agent.16 It is used tor the 1,2-reduction of acyclic and cyclic enones. Esters and lactones are reduced at room temperature to alcohols, and at -78 C to alcohols and aldehydes. Acid chlorides are rapidly reduced with excess reagent at -78 C to alcohols, but a mixture of alcohols, aldehydes, and acid chlorides results from use of an equimolar amount of reagent at -78 C. Acid anhydrides are reduced at -78 C to alcohols and carboxylic acids. Carboxylic acids and both primary and secondary amides are inert at room temperature, whereas tertiary amides (as in the present case) are reduced between 0 C and room temperature to aldehydes. The at complex rapidly reduces primary alkyl, benzylic, and allylic bromides, while tertiary alkyl and aryl halides are inert. Epoxides are reduced exclusively to the more highly substituted alcohols. Disulfides lead to thiols, but both sulfoxides and sulfones are inert. Moreover, this at complex from DIBAH and butyllithium is able to reduce ketones selectively in the presence of esters. 

These organocopper reagents (equation I) react with various electrophiles, aldehydes, acid chlorides, enones, allylic bromides, in 85-95% yield."... 

An important recent advance in the area is the demonstration that allyl chlorides readily form allylcopper species upon exposure to highly activated copper ( Rieke copper ). The resultant allylcoppers have been shown to react with a fairly wide range of nucleophiles (ketones, aldehydes, acid chlorides, enones, epoxides [after conversion to the cuprate], imines, and allyl bromides)56. Regiochemical considerations in such substitutions depend upon the cases studied, and are fairly complex. The allylcoppers formed have, in all cases, the least substituted C—Cu bond allyl transfer from these reagents is selective from the imposition of the allyl (enone electrophiles excepted)(equations 41 and 42). The allyl chloride... 

Q Predict the products and propose mechanisms for the reactions of amines with ketones, aldehydes, acid chlorides, nitrous acid, alkyl halides, and oxidizing agents. 

Propose single-step and multistep syntheses of amines from other amines, ketones, aldehydes, acid chlorides, nitro compounds, alkyl halides, nitriles, and amides. 

Aldehydes. Acid chlorides are reduced to aldehydes with HCOOH-NH OH under nitrogen. 

The a-alkylation of amines is a valuable synthetic transformation. The amino group itself is not suflBciently activating to allow conversion of an a-methyl (R2N—Me) (or methylene) group into an alkali-metal salt (R2N—CH2—M), but certain derivatives of secondary amines can be converted into lithium salts with a strong base. The resulting a-amino-organolithium species react readily with alkyl halides, aldehydes, acid chlorides and other electrophiles. Successful results have been obtained with A -nitroso derivatives, various sterically hindered amides or for-mamidines. For example, dimethylamine can be converted into the amines 91 and 92 via the formamidine 90 (1.95). ... 

Decarbonylations. Wilkinson s catalyst has been known for some time to decarbonylate aldehydes, even heavily functionalized ones, to the corresponding hydrocarbons. Some examples are shown in eqs 30-33, illustrating high stereochemical retention in the decarbonylation of chiral, cyclopropyl, and unsaturated aldehydes. Acid chlorides are also decarbonylated by RhCl(PPh3)3-... 

Nelson s group induced the formation of c/s-p-lactones using the combination of alkaloids (O-TMS-QD or O-TMS-Q) and a mild Lewis acid (LiCl04) starting from acid halides and aliphatic aldehydes (acid chloride-aldehyde cyclocondensation, AAC) ensuring high enantio- and diastereoselectivity (Scheme 15.11). Their studies were then expanded to chiral aldehyde... 

Arylcarbonyl compounds, such as carboxylic acids, aldehydes, acid chlorides, amides, and esters, have been increasingly used as an aryl source in arene-assembling cross-coupHng reactions. They are usually inexpensive and readily available compared to general cross-coupling partners [155]. In addition, these coupling reactions produce CO or CO2 as a by product instead of toxic metal halides. 

In previous sections, hydride reagents such as NaBH4 or LiAlH4 reduce ketones or aldehydes and most acid derivatives to the corresponding alcohol. LiAlH4 reduces amides to amines and also reduces nitriles to amines. Catalytic hydrogenation reduces alkenes and alkynes, as well as ketones, aldehydes, acid chlorides, and nitriles. Acid chlorides may be reduced to aldehydes, and nitriles are also reduced to amines by catalytic hydrogenation. 

Preparation of C7F15CHO. Catalyst 10% Pd/C (200 mg) was placed in a 3-necked round-bottomed flask and cooled at 0 °C. Triisopropylsilane (3.32 g, 21 mmol) was added, followed by perfluorooctanoyl chloride (7.9 g, 18.2 mmol). The mixture was allowed to warm to room temperature and was then controlled at 25-27 °C during the exothermic reaction. After 3 hr, GC analysis showed an aldehyde/acid chloride ratio = 94/6. Another 0.26 mL of... 

It will also reduce acid chlorides, acid anhydrides and aldehydes to primary alcohols, ketones to secondary alcohols, and amides to the corresponding amines R-CONHi -> R CHiNH. Nitro-hydrocarbons if aromatic are... 

Almost insoluble in cold water. Higher alcohols (including benzyl alcohol), higher phenols (e.g., naphthols), metaformaldehyde, paraldehyde, aromatic aldehydes, higher ketones (including acetophenone), aromatic acids, most esters, ethers, oxamide and domatic amides, sulphonamides, aromatic imides, aromatic nitriles, aromatic acid anhydrides, aromatic acid chlorides, sulphonyl chlorides, starch, aromatic amines, anilides, tyrosine, cystine, nitrocompounds, uric acid, halogeno-hydrocarbons, hydrocarbons. 

Acid Chlorides -r H2, Pd/BaS04 Aldehydes (Rosemund Reduction)... 

The reduction of acyl halides with hydrogen to form aldehydes using Pd catalyst is well known as the Rosenmund reduction[756]. Some acyl chlorides give decarbonyiation products rather than aldehydes under Rosenmund conditions. The diene 890 was obtained by decarbonyiation in an attempted Rosenmund reduction of acetyloleanolic acid chloride (889)[757], Rosenmund reduction of sterically hindered acyl chlorides such as diphenyl- and tnpheny-lacetyl chloride (891) gives the decarbonylated products 892[758],... 

The hydroxyl group can be esterified with acid chlorides, anhydrides, or carboxyUc acids and it reacts with aldehydes (12) or vinyl ethers (13) in the presence of an acid catalyst to form acetals. 

Sulfur tetrafluoride [7783-60-0] SF, replaces halogen in haloalkanes, haloalkenes, and aryl chlorides, but is only effective (even at elevated temperatures) in the presence of a Lewis acid catalyst. The reagent is most often used in the replacement of carbonyl oxygen with fluorine (15,16). Aldehydes and ketones react readily, particularly if no alpha-hydrogen atoms are present (eg, benzal fluoride [455-31-2] from benzaldehyde), but acids, esters, acid chlorides, and anhydrides are very sluggish. However, these reactions can be catalyzed by Lewis acids (HP, BF, etc). 

Aldehyde Synthesis. Formylation would be expected to take place when formyl chloride or formic anhydride reacts with an aromatic compound ia the presence of aluminum chloride or other Friedel-Crafts catalysts. However, the acid chloride and anhydride of formic acid are both too unstable to be of preparative iaterest. 

Hydride reagents Aldehyde Ketone Acid chloride Ester Carboxyhc acid Carboxyhc salt Amide... 

A particularly useful reaction has been the selective 1,2-reduction of a, P-unsaturated carbonyl compounds to aHyUc alcohols, accompHshed by NaBH ia the presence of lanthanide haUdes, especially cerium chloride. Initially appHed to ketones (33), it has been broadened to aldehydes (34) and acid chlorides (35). NaBH by itself gives mixtures of the saturated and unsaturated alcohols. 

Acids and esters (see Esters, organic) are less easily brominated than aldehydes or ketones. Acid chlorides and anhydrides are more easily brominated (23). 

Reduction of Acid Chlorides to Aldehydes. Palladium catalysis of acid chlorides to produce aldehydes is known as the Rosenmund reduction and is an indirect method used in the synthesis of aldehydes from organic acids. 

Esters are most commonly prepared by the reaction of a carboxyHc acid and an alcohol with the elimination of water. Esters are also formed by a number of other reactions utilizing acid anhydrides, acid chlorides, amides, nitriles, unsaturated hydrocarbons, ethers, aldehydes, ketones, alcohols, and esters (via ester interchange). Detailed reviews of esterification are given in References 1—9. 

The methylhydrazone of acetophenone (112) underwent ready reaction with n-butyl-lithium giving the dianion (113) reaction with acid derivatives such acid chlorides or esters resulted in pyrazole (114) formation whereas with aldehydes, pyrazolines were obtained (76SC5). With dichloromethyleneiminium salts (115), 5-dimethylaminopyrazoles... 

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