Functional Groups with Triple Bonds

Reactions with other carbon triple bonded functional groups. The substitution of nitrile for alkynes does not lead to pyridines or quinolines in the benzannulation reaction.Instead noncyclic products are obtained that are the result of insertion of the carbon-nitrogen triple bond into the metal-carbene bond. On the other hand, in a very recent report it was found that X -phosphaalkynes will undergo the benzannulation reaction to produce phosphaarene chromium tricafbonyl complexes. 

However, if we are to understand and classify the varied bonding models in metallo-organics, then the systematic analysis of crystallographic results for carefully chosen classes and subclasses of these compounds represents an essential starting point. Indeed, crystal structure analysis has underpinned the rapid developments in metallo-organic chemistry, particularly over the past 10-15 years, to the extent that some 48% of CSD entries now fall into this category. For these reasons, no modern review of triple-bonded functional groups would be complete without some consideration of their interaction with metal centres. 

The first supplementary volume dealing with the chemistry of triple-bonded functional groups (—C=C—, —C=N, —N=N and related groups) was published in 1983. Since that time, the subject has advanced considerably, and the chapters contained in the present Supplement C2 volume treat almost exclusively material which was reported in the last fifteen years. In most cases the literature was covered up to the middle or end of 1992 and less often up to the beginning of 1993. 

An extension of this approach led to the study of some simple molecules in which trivalent phosphorus is bonded to carbon by a double or a triple bond. These spectroscopic experiments have not only yielded conclusive identification but a wealth of molecular information such as geometric and electronic structural data. More importantly, the >C=P- and -CSp moieties could be considered as viable functional groups with interesting and well defined chemical properties. 

Thus, the majority of known lepidopteran pheromones are comprised of compounds that are between 10 and 23 carbons in length, with one or no polar functional groups. Within these broad limits, there are two major structural classes, each of which arises from different biosynthetic pathways. The first class, designated as Type I pheromones (Ando et al., 2004) consists primarily of alcohols, aldehydes, and acetates with unbranched carbon chains of 10-18 carbons, and with 0-3 double bonds. Unusual structures or functional groups, such as triple bonds, nitro groups, or esters other than acetates, are occasionally... 

Functional groups with double or triple bonds undergo addition. 

There are only two important functional groups with triple bonds, Alkynes, with their electron-rich —C C— group, undergo addition (by H2O, H2, HX, X2, and so forth) to form double-bonded or saturated compounds ... 

The alkyne-Co2(CO)6 complexes 1 are the binuclear cluster complexes of the acetylenic derivatives with the hexacarbonyldicobalt moiety. These complexes can be readily prepared by treatment of alkynes with commercially available octacarbonyldicobalt [Co2(CO)g] and can regenerate the parent triple bond functionality under some mild oxidation conditions. Two synthetically very useful reactions have so far been developed by taking advantage of the characteristic properties of the alkyne-Co2(CO)6 complexes 1 one is so-called Nicholas reaction" and the other is so-called Pauson-Khand reaction (Scheme 1). The alkyne-Co2(CO)6 complexes 1 possessing a hydroxyl group or its equivalent at carbon p- to alkyne moiety (propargyl alcohol derivatives) could easily... 

Alkynes and nitriles are the only two important functional groups with triple bonds. 

Functional groups with double or triple bonds—alkenes, aldehydes, ketones, alkynes, and nitriles—generally take part in addition reactions. 

After discussing many examples from the fields of double bonds, triple bonds, and various representative carbonyl groups, we start the section on sp -based functional groups with the preparation and ring-opening reactions of epoxides. 

Ferrate(VI) Ion (K2Fe04) rapidly oxidizes primary amines and alcohols to aldehydes and secondary alcohols to ketones without affecting double or triple bonds, aldehyde groups, or tertiary alcohol or amine functions. Oximes are converted to aldehydes and ketones virtually Instantaneously with T1(N03)3. °... 

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