Polyfunctionalized aromatic

These reactions complement recently developed palladium(0)amination reactions [146,147,148] and related procedures using a copper(I) [149] - or ni-ckel(O) [151] - catalysis. As indicated above, the mild reaction conditions are compatible with a range of functional groups. Functionalized arylmagnesium chlorides such as 309 prepared by an I/Mg-exchange readily undergo addition reactions to aryl oxazolines. The addition-elimination of 309 to the -methoxy aryloxa-zoline followed by an ortHo-lithiation and substitution with ethylene oxide leads to a polyfunctionalized aromatic intermediate 310 for alkaloid synthesis (Scheme 4.68) [165]. 

This reaction has been extensively used for the synthesis of polyfunctionalized piperidines with a wide range of nucleophiles selected and representative examples are collected in Table 15. From these results, hydrides, Grignard reagents, aluminium derivatives, allylsilane, as well as aromatics can be used as nucleophiles to give the corresponding C-8a functionalized compounds in good yields and, in most cases, excellent selectivities. 

Similar to epoxy novolac resins, tetraglycidyl ether of tetraphenolethane resin is usually employed in a blend with lower-MW liquid resins. The high aromatic ring content combined with polyfunctionality provides increased thermal stability for high-temperature applications. The chemical resistance and humidity resistance of cured tetraglycidyl ether of tetraphenolethane epoxy resins are also outstanding. 

The use of norbomene as a scaffold for aromatic C-H functionalization, a process we dubbed the Catellani Reaction, is a useful and mechanistically interesting method for the polyfunctionalization of aromatic molecules. Through the development and study of palladium complexes with norbomene, a powerful synthetic method has emerged which has been proven useful primarily through the research efforts of Catellani and Lautens. Future studies in this area should focus on expanding the already wide variety of products available, and to develop and/or utilize new reactions which can be performed on either the palladacycle intermediate or terminal arylpalladium(II) species. 

En route to the synthesis of mensacarcin (104), a polyfunctionalized hexahy-droanthracene, showing cytostatic and cytotoxic activity, Tietze et al. [49] devised a Mizoroki-Heck cyclization for the formation of the tricyclic core. Several substrates with different protecting groups and substitution patterns were tested, out of which 102 turned out to be the best, affording 103 in 94% yield under optimized reaction conditions (102 103, Scheme 5.20). A similar strategy was pursued by Banerjee and coworkers [50] for the synthesis of tetrahydroanthracenes leading to umbrosone (107). Variation of the substituents in 105 had a minor effect, the reactions proceeded smoothly in 84-86% yield (105 106), and subsequent elimination of H2O provided the tetrahydroanthracene core. When diene 108 was employed the aromatic system in 109 was directly installed by double-bond migration (108 109). 

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