Carbonyl group derivatives tolerated

In 2006, Ukai et al. proposed an interesting alternative with a rhodium(I)-catalyzed carboxylation of aryl- and alkenylboronic esters proceeding under mild conditions, and leaving ancillary reactive functional groups such as carbonyl- and cyano unreacted [51] (Scheme 5.13). Considering that organoboronic esters are easily available, and that various functional groups are tolerated, this reaction appeared to be particularly useful for the preparation of functionalized arylcarboxylic acids, such as benzoic and cinnamic acid derivatives. 

The other way to prepare cyclopropanes is based on the spin-center-shift. Thus, aryl-alkyl ketones, 26, bearing a leaving group X adjacent to the excited carbonyl group undergo a smooth cyclization to benzoylcyclopropanes 27 in moderate to good yields (Scheme 6b) [4a, b]. The reaction tolerates a variety of functional groups, often proceeds stereoselectively, and can be extended to the preparation of bicyclo[n.l.O]alkane derivatives. 

Mono-, di- and trisubstituted alkenes can all be prepared in good yield by the Wittig reaction. A large variety of ketones and aldehydes are effective in the reaction, although carboxylic acid derivatives such as esters fail to react usefully. The carbonyl compound can tolerate several groups such as OH, OR, aromatic nitro and even ester groups. 

The scope of the reaction is quite broad, and a number of functional groups are tolerated in the reaction. Radicals generated at the carbonyl of an amide or a to an alcohol, ether (45) or amine can be utilized in the Minisci reaction. Minisci, later, showed homolysis of sugar-derived alkyl iodides 46 under thermal conditions to give carbon-centered radicals. These radicals undergo HAS to quinoline derivatives 47 and other heteroaromatics in good yields. Cowden showed that decarboxylation of commercially available a-amino acids 48 can form a carbon-centered radical for use in the Minisci reaction. ... 

In addition, the palladium-catalyzed C-H carbonylation is also useful to construct pyranone derivatives. In 2011, Yu s group reported a Pd(II)-catalyzed ortho-C-H carbonylation reaction of phenethyl alcohol derivatives to give 1-isochromanones by connecting the aryl moiety and alcohol with incorporated carbonyl group (Scheme 3.24) [49]. A wide range of functionahties such as methoxy, fluoro, chloro, and bromo are tolerated under the typical condition and afford various 1-isochromanones in moderate to good yields. The A-protected amino acids are supposed to reduce the rate of Pd(II) reduction in the presence of CO in this work. 

Scheme 10.18) [44]. The use of the catalytic system used in the annulation with olefins (Scheme 10.17) under an atmosphere of carbon monoxide and air effects ort/zo-carbonylation of benzamides and concomitant C-N bond formation, thus affording phthalimide derivatives in moderate to excellent yields. As is the case with the annulation reactions of alkynes and olefins, the carbonylation reaction exhibits tolerance to a broad range of functional groups. The quinolinyl group on the product can be removed by treatment with ammonia. 

Since various substituents are tolerated, the Friedlander reaction is of preparative value for the synthesis of a large variety of quinoline derivatives. The benzene ring may bear for example alkyl, alkoxy, nitro or halogen substituents. Substituents R, R and R" also are variable. The reaction can be carried out with various carbonyl compounds, that contain an enolizable a-methylene group. The reactivity of that group is an important factor for a successful reaction. 

Despite the rich chemistry of 288 that may be anticipated, " " synthetic methods for this type of compounds are limited to the one involving oxidation of the corresponding alcohols. In contrast, 288 is readily derived from 287 by a simple and one-pot operation. Since propargylic alcohols are readily accessible from ketones or aldehydes, the straightforward transformation from 70 to 288f provides a novel method for carbonyl olefination of ketones and aldehydes. For example, ethisterone, 301, is tolerable to this transformation (route 2, Scheme 16) without any protection of the functional groups to give 302 (Equation (51))." ... 

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