Inter- and Intramolecular Additions

The explanation proposed involved sequential inter- and intramolecular addition steps. The presence of cyclic structures within the polymer chain was soon confirmed by degradation experiments.106 However, these experiments did... 

It is interesting to note that the oxa-analogous Michael addition was reported for the first time in 1878 by Loydl et al. [19] in their work on the synthesis of artificial malic acid, which was five years ahead of the discovery of the actual Michael reaction described first by Komnenos [20], Claisen [21], and later Michael in 1887 [22] as one of the most important methods for C—C bond formation. In continuation of the early work on the oxa-Michael addition [23], the inter- and intramolecular additions of alkoxides to enantiopure Michael acceptors has been investigated, leading to the diastereo- and enantioselective synthesis of the corresponding Michael adducts [24]. The intramolecular reaction has often been used as a key step in natural product synthesis, for example as by Nicolaou et al. in the synthesis of Brevetoxin B in 1989 [25]. The addition of oxygen nucleophiles to nitro-alkenes was described by Barrett et al. [26], Kamimura et al. [27], and Brade and Vasella [28]. 

Substituted cyclopropylidenes have been shown to participate in both inter-and intramolecular addition reactions with olefins. The resulting products are spiropentane derivatives as well as carbene dimers which are formed as side-products [99, 100]. In the absence of olefinic reaction products the latter may even become the main products [99 b],... 

The transition metal-catalyzed addition of alcohols to unsaturated systems has not been widely investigated. Reports on addition of alcohols to 1,3-diene [24] or allene [25] have appeared but have very limited scope. We recently reported the palladium/benzoic acid-catalyzed inter- and intramolecular addition of alcohols to alkynes in which various acyclic and cyclic allylic ethers are produced [26], The Pd-catalyzed addition of alcohols to alkylidenecyclopropanes proceeds smoothly providing a powerful tool for synthesis of allylic ethers [27a]. An intramolecular version of the hydroalkoxylation has been demonstrated in which the phenol-tethered alkylidenecyclopropanes undergo facile cyclization to give exomethylene products [27b],... 

The radical addition to 1-alkenyl or 1-alkynylboronic esters or amides took place extremely smoothly because the boron atom stabilizes the resulting ct-radical intermediates. Bu3SnH and PhSH predominated the trans-addition products 287 in the addition to 1-alkynylboronic amides at 90 °G, whereas Bu3SnH and Ph2Ph produced the m-addition products 288 at 0°C (>98% Equation (82)).455 Intramolecular addition to 1-alkenylboronic esters has been demonstrated in boron-tethered radical cyclization that provided 1,3- or 1,4-alkanediols 290 via oxidative workup (Equation (83)).456 Inter- and intramolecular additions of alkyl radical457 and sulfonyl radical458 have also been studied. 

Gilbert s group report some new results for the inter- and intramolecular addition of polarised alkenes to naphthalenes. It is found that the bichromophoric system (113) undergoes intramolecular addition to give (114) while... 

A number of examples of inter- and intramolecular additions of ailyl silanes to N-sulfonyl imines have been reported. Weinreb and coworkers have combined the Kresze methodology for forming A-sulfonyl imines and subsequent additi-... 

E. Inter- and Intramolecular Addition of Nucleophiles to C-4 of Pyrazol-3-ones.. 219... 

Combination of allyl radicals that result from hydrogen abstraction at methylene groups a to double bonds may give rise to dimeric compounds. Such radicals may also undergo disproportionation or inter- and intramolecular addition to C-C double bonds. Dimerization of unsaturated fatty acids can also occur via Diels-Alder reactions. In the case... 

Allyl silanes are a species of carbon nucleophile that has performed well in combination with oxidative dearomatization induced by hypervalent iodine reagents [65]. Inter- and intramolecular additions of allyl silanes to putative phenoxonium cations have been reported, and the latter reaction type provided a key transformation in the synthesis of the potent antibiotic (-)-platensimycin (Scheme 15.23) [66]. 

The gold-catalyzed inter- and intramolecular addition of carbon- and heteronucleophiles to alkynes leads to a wide variety of products [6]. In the case of nitrogen nucleophiles, the addition of amines, anihnes [67, 68], imines [69], pyridines and azides [72] is possible (Scheme 1.1). 

Inter- and intramolecular additions of alkenes and dienes to propargylic alcohols catalyzed by thiolate-bridged diruthenium complexes have been described. The processes, a kind of allenylidene-ene reaction, generate 1,5-enynes and dienynes by reaction of propargylic alcohols with 2-arylpropenes [196] and 1,3-conjugated dienes [197], respectively. The intramolecular version of this reac-ti(Mi has been developed to give diastereo- [196, 198] or enantioselective syn-substituted chromanes (Scheme 58) [199]. Recently, the results of DPT calculations indicated that nucleophilic attack of the olefinic Jt-electrons on a carbocationic... 

Scheme 58 Ru-catalyzed inter- and intramolecular additions of alkenes and dienes to propargylic alcohols to 1,5-enynes and dienynes...

Dufiach et a. successfully added thiolacetic acid to alkenes using either InCls or In(OTf)3 as catalysts [105]. The same system, but with ln(OTf)3, was used for both inter- and intramolecular addition of thiols to alkenes. These reactions proceed with high Markovnikov regioselectivities, with most reactions producing only one regioisomer. Non-Markovnikov additions were observed for vinyl cyclohexane, owing to isomerization of the double bond. (Figure 8.52)... 

Mariano, P.S., SET-Induced inter- and intramolecular additions to iminium cations, in CRC Handbook of Organic Photochemistry and Photobiology, Horspool, W.M. and Song, P.-S., Eds., CRC Press, Inc., Boca Raton, FL, 1995, p. 867. 

Abstract Progress in the field of inter- and intramolecular additions of oxygen nucleophiles (water, alcohols, phenols, and carboxylic acids) to alkenes, allenes, alkynes, and nitriles catalyzed by Co, Rh, Ir, Ni, Pd, and Pt is critically reviewed. 

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