Substitution with carbon

A different approach was used by Ainai, starting from azidopentane 91 04JOC655 . (-)-Aristeromycin 94 was obtained after building the adenine ring from the reduced form of 93. A third approach published consisted of building a carbocycle from D-ribose, and condensing the 

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Iridium-Catalyzed Allylic Substitution with Carbon Nucleophiles... 

Phenoxide ion generated by treating phenol with sodium hydroxide is even more reactive than phenol towards electrophilic aromatic substitution. Hence, it undergoes electrophilic substitution with carbon dioxide, a weak electrophile. Ortho hydroj benzoic acid is formed as the main reaction product. 

ElectrophiHc substitutions with carbon and hetero electrophiles a to the carbonyl group of aldehydes and ketones are among the most important synthetic operations. Such regio-, diastereo-, and enantioselective substitutions can be carried out efficiently with the SAMP/RAMP hydrazone methodology [3]. For cases where virtually complete asymmetric inductions could not be attained, an alternative approach based on a-silylated ketones 2 was developed [4]. They can be prepared easily from ketones 1 in high enantiomeric purity (ee > 98%) by asymmetric carbon silylation employing the SAMP/RAMP hydrazone method (Fig. 1.1.1). After the introduction of various electrophiles via classical enolate chemistry with excellent asymmetric inductions, the desired product ketones 3... 

Nucleophile addition-substitution with carbon nucleophiles 531... 

The presence of different elements attached to boron atom does not significantly alter the chemical shifts. Diazaboroles 9a-e substituted with carbon (8 29.5), silicon (8 29.9), germanium (8 30.5), tin (8 32.8), and lead (8 39.6) <2003AOM525>, as well as dioxaborolanes lOa-g substituted with sulfur (8 34.3), selenium (8 35.3), silicon... 

Thiadiazole 1-monoxides react analogously <8iH(l6)i56i, 81H(16)1565). When alkythio is the leaving group, substitution with carbon nucleophiles can be accomplished. Thus, the methylthio analog (33) reacts smoothly with malonate anion to form (34). Analogous... 

Phenoxide ions are so strongly activated that they undergo electrophilic aromatic substitution with carbon dioxide, a weak electrophile. The carboxylation of phenoxide ion is an industrial synthesis of salicylic acid, which is then converted to aspirin, as shown on p. 802. 

C-Glycosylation reactions of glycosyl-halide, -ester and -ether with carbon nucleophiles are divided into two types the Sn2 type of substitution with carbon nucleophiles such as Grig-nard reagents, and addition of carbon nucleophiles to oxocarbenium cations generated from... 

When ethylene was substituted with carbon monoxide, the propionyl compound was formed ... 

The presence of both an oxygen and an amino substituent (see also 14.10) can allow substitution with carbon electrophiles. ... 

Thus the arylation cannot be considered as a model of general validity for the homolytic aromatic substitution, not even for substitutions with carbon free radicals. 

Allylic aeetates or carbonates can undergo nucleophilic substitutions via palla-dium(0)-catalysis (11). In this paper, we report on the extension of this reaction to unsaturated fatty aeids by the preparation of allyl carbonates and acetates of oleic, linoleic, and 10-undecenoic acid and their substitution with carbon- and heteroatom-nucleophiles by palladium(0)-catalysis. In this way, different substituents can be in-trodueed into the alkyl chain of fatty acids. This leads to fatty acid derivatives in which the properties of biologically active compounds may possibly be combined with the amphiphilic property of the fatty acid. 

The synthesis of benzo[i ]furan derivatives has become a very active field because these molecules have been identified as having a variety of biological aaivities. Many syntheses of interesting benzo[f ]furans substituted with carbon, oxygen, nitrogen, or sulfur functional groups at the C-2/C-3 position were reported in 2014. 

A Stereoselective Synthesis volume of the Science of Synthesis series has reviewed the alkylation and allylation of carbonyl and imino groups, as well as the enantio-selective addition of metal alkynylides to imino and carbonyl compounds. Recent advances in Favorskii rearrangement, Sonogashira reactions, and catalytic enantio-selective allylic substitutions with carbon nucleophiles have been highlighted. 

On the other hand, allylic-type aluminum exhibits facile rearrangement as shown in Eq. (1). The dialkylaluminum of the allylic-type aluminun is substituted with carbon dioxide, acyl chlorides and silicon chlorides. ... 

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