Benzamide, intermolecular

The need of the acylurea site participating in intermolecular hydrogen bonding (cf. Figs. 11 and 12) for the complex formation is exemplified by the fact that a 1 1 mixture of JV-(p-dimethylaminophenyl)phenylacetamide (21) and JV-isobutyl-p-nitro-benzamide (22) gives no crystalline complexes under the same conditions as with 19 and 20. The trend of the complex formation often changes, when the combinations of R7 and R8 are reversed 35). 

The intermolecular ruthenium enyne Alder-ene reaction has been extended to the stereoselective preparation of enamines (Equation (26)).39 The yields obtained for this reaction were high with allylacetamides, -benzamides,... 

An Ir(l)-catalyzed asymmetric intermolecular hydroarylation of norbornene with benzamide was reported in good to excellent enantiomeric excess, albeit in low yields, via the aryl C—H activation (Scheme 5.14). In some cases, the hydroami-nation products of norbornene were also formed in high enantioselectivities. 

Intermolecular additions of the O-H bonds of phenols and alcohols and the N-H bonds of sulfonamides and benzamide to alkenes catalysed by 1 mol% of triflic acid have been reported as tools for the synthesis of cyclic ethers and amines. This study contributed to defining the relationship between these reactions and those catalysed by metal triflates.36... 

As shown by the last reaction in Scheme 5.23, the metalation of benzamides is complicated by several potential side reactions (Scheme 5.24). Thus, benzamides can also undergo ortho-metalation [181, 217-222] or metalation at benzylic positions [223-225], Ortho-metalation seems to be promoted by additives such as TMEDA, and benzylic metalation can be performed selectively with lithium amide bases [217,224], which are often not sufficiently basic to mediate ortho- or a-amino metalation. If deprotonation of the CH-N group succeeds, the resulting product might also undergo cydization by intramolecular attack at the arene [214, 216] (see also Ref. [226] and Scheme 5.27) instead of reacting intermolecularly with an electrophile. That this cydization occurs, despite the loss of aromatidty, shows how reactive these intermediates are. 

Fig. 2 Intermolecular interactions in benzamide crystal showing the carboxamide dimers and hydrogen-bonded chain. (From Ref. l)...

In addition to amines, some derivatives of amines can be arylated. Weakly basic amides are arylated, and intermolecular reactions between aryl bromides and tri-flates 48 with benzamide can be carried out. Combined uses of xantphos (IX-IO) and CS2CO3 in THF or dioxane gave the most successful results. The cyclic urea 49 was diarylated [40]. Sulfonamides are also arylated [41]. Intramolecular reaction of the secondary amides such as 50 or carbamates offers convenient synthetic methods for five-, six-, and seven-membered lactams like 51. As ligands, MOP (VI-12), DPEphos (IX-9), xantphos (IX-IO), and BINAP are used depending on the size of the rings. As an example, ligand IX-9 is the most suitable for the preparation of the five-membered A-carbobenzyloxy derivative 52a from 52, but BINAP was not effective. 

Scheme 5.59 Ir-catal) ed asymmetric intermolecular hydroarylation of nor-bornene with benzamide reported by Togni.

Organic componnds are susceptible to forming various intermolecular interactions and hence there is an increased chance of polymorphism. Benzamide is one of the earliest... 

A new Rh(III)-catalyzed intermolecular annulation of Af-methoxybenzamides with a, -unsaturated aldehydes or ketones to afford azepinones 118 was reported by Glorias eta/. (Eq. (5.109)) [56a]. The reaction involves a tandem C-H activation, cyclization, and condensation sequence. The substrates with other A/-substituents, such as H, phenyl, and OPiv, did not afford the corresponding products. Vinylcarbenoids were also used as the three-carbon component in the Rh(III)-catalyzed C-H activation and [4-1-3] cycloaddition with benzamides to access azepinones (Eq. (5.110)) [56b]. 

Indole and isoquinolone nuclei are prominent structural units frequently found in numerous natural products and pharmaceutically active compounds. Thus, the search for new methodologies to obtain these scaffolds with different substitution patterns is a current major objective in organic synthesis. Similar to benzofuran synthesis, Aluraez et al. observed that the palladium-catalyzed cascade intramolecular alkyne aminopaUadation/intermolecular Heck-type coupling reaction under oxidative conditions is an efficient methodology for the synthesis of indole 217 and isoquinolone 219 derivatives, starting from readily available aniline 216 or benzamide 218 substrates and functional alkenes [77] (Scheme 6.60). 

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