Carbon sections

Benzylic carbon (Section 11 10) A carbon directly attached to a benzene nng A hydrogen attached to a benzylic carbon is a benzylic hydrogen A carbocation in which the benzylic carbon is positively charged is a benzylic carbocation A free radical in which the benzylic carbon bears the unpaired electron is a benzylic radical Benzyne (Section 23 8) The compound... 

Primary carbon (Section 2 13) A carbon that is directly at tached to only one other carbon Primary structure (Section 27 8) The sequence of ammo acids in a peptide or protein... 

Quaternary carbon (Section 2 13) A carbon that is directly at tached to four other carbons... 

Anomeric carbon (Section 25.6) The carbon atom in a fura-nose orpyranose form that is derived from the carbonyl carbon of the open-chain form. It is the ring carbon that is bonded to two oxygens. 

Peptidomimetics are peptide molecules characterized by modifications to the side chain (Section 9), to the a-carbon (Sections 10.3 and 10.4), or, to the components of a peptide bond itself either singularly (e.g., Sections 10.1 and 10.2), or, in combination. Peptidomimetics containing a modification to the nature of the peptide bond are often referred to as pseudopeptides or peptide bond surrogates. 1 These compounds are sometimes termed as peptide bond isosteres, although the isosteric nature of the replacement is often not obvious or may even be dubious. 

There are several analogies for this kind of rearrangement that involve electron-deficient carbon (Sections 8-9B and 15-5E) and oxygen (Sections 16-9E). 

Exercise 28-32 Quinones react with nucleophilic agents at carbon (Section 26-2D) ... 

When represented in this way the chemistry of carbonyl complexes of transition metals becomes easier to understand. Hydroformylation reactions and other carbonylations that are catalyzed by transition-metal complexes frequently involve hydride or alkyl transfers from the metal atom to the positive carbonyl carbon (Sections 16-9G, 31-3, and 31-4) ... 

This chapter represents an update to the previous two editions, published in 19771 and 19892, and covers the literature of the period 1989-1994 with some references to 1995 papers. It deals mainly with electrophilic additions across the C=C, C=Si and Si=Si bonds and includes both theoretical (ab initio calculations, orbital approach, molecular modelling etc.) and experimental aspects. Particular attention is paid to mechanistic studies, facial selectivity and neighbouring group participation. Synthetic utilization of electrophilic addition is discussed only if including substantial mechanistic insight purely synthetic work is not covered. Aside from the classical reactions, such as hydration, bromination etc., newly included material comprises aziridination (Section VI), attack at C=C bond by an electron-deficient carbon (Section VII) and those electrophilic reactions which utilize a transition or non-transition metal as the electrophile (Section VIII). 

Alpha-carbon (cr-carbon) (Section 12.3) The carbon adjacent to a functional group most commonly used to refer to the carbon adjacent to a carbonyl group. 

Primary carbon (Section 5.3) A carbon that is bonded to one other carbon. 

Considering these heats of deprotonation, one wonders whether organolithium compounds should not be at least as suitable as lithium amides for effecting the deprotonation of carbonyl and carboxyl compounds. However, this is usually not the case, since organolithium compounds react almost always as nucleophiles rather than as bases. Organolithium compounds thus would add to the carbonyl carbon (Section 8.5) or engage in a substitution reaction at the carboxyl carbon (Section 6.5). 

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