C-H bond alkenylation

C—H bond alkenylations, 10, 222—223 in cross-coupling polymerization, 11, 687 N-Heteroaromatic compounds, hydrogenation, 1, 792 Heteroaromatic stannanes, preparation, 3, 828 Heteroaryl halides, aminocarbonylatioon, 11, 527 Heteroarylstannanes, preparation, 3, 826 Heteroatoms... 

Platinum complexes (continued) with aryls, thallium adducts, 3, 399 with bis(alkynyl), NLO properties, 12, 125 with bisalkynyl copper complexes, 2, 182-186 with bis(3,5-dichloro-2,4,6-trifluorophenyl), 8, 483 and C-F bond activation, 1, 743 in C-H bond alkenylations, 10, 225 in C-H bond electrophilic activation studies, 1, 707 with chromium, 5, 312 with copper, 2, 168 cyclometallated, for OLEDs, 12, 145 in diyne carbometallations, 10, 351-352 in ene-yne metathesis, 11, 273 in enyne skeletal reorganization, 11, 289 heteronuclear Pt isocyanides, 8, 431 inside metallodendrimers, 12, 400 kinetic studies, 1, 531 on metallodendrimer surfaces, 12, 391 mononuclear Pt(II) isocyanides, 8, 428 mononuclear Pt(0) isocyanides, 8, 424 overview, 8, 405-444 d -cP oxidative addition, PHIP, 1, 436 polynuclear Pt isocyanides, 8, 431 polynuclear Pt(0) isocyanides, 8, 425 Pt(I) isocyanides, 8, 425 Pt(IV) isocyanides, 8, 430... 

Pd-Catalyzed C-H Alkenylation of Indole and Pyrrole 4.1 Mechanisms of Pd-Catalyzed C-H Bond Alkenylation... 

An early example of a natural product synthesis featuring an indole C-H bond alkenylation was report by Trost and co-workers (Scheme 54). Using stoichiometric Pd(II)-salts in combination with silver tetrafluoroborate, they were able to mediate a oxidative Heck process onto the bicyclic amino-alkene. Using a reductive work-up to reduce the Pd-C bond, they were able to complete a synthesis of ibogamine [76]. 

Meanwhile, direct C-H bond alkenylation reactions have been developed to provide more simple synthetic routes for alkenylarene derivatives. As the first example, in 1967, Moritani and Fujiwara [1] reported dehydrogenative alkenylation of benzene with styrene in the presence of a stoichiometric amount of a palladium complex to produce stilbene (Scheme 18.1). Later, these authors succeeded in conducting the reaction in a catalytic manner by using an appropriate oxidant (the Fujiwara-Moritani reaction. Section 18.2.1) [2]. Unfortunately, the reaction of substituted benzenes such as toluene usually gave a mixture of regioisomers of alkenylated products. 

Scheme 18.3, Section 18.4). In this chapter, the progress that has been achieved with such catalytic C-H bond alkenylation reactions is reviewed. 

T8.3 Direct C-H Bond Alkenylation with Alkenyl Halides and Aikenyimetai Reagents 1413... 

Oi, Inoue, and coworkers reported C-H bond alkenylation reactions of 2-phenylpyridine [65] and 2-phenyloxazoUne derivatives [66] and of aromatic imines [67] with alkenyl bromides under Ru catalysis (Scheme 18.66 and Scheme 18.67). 

Besides halides, alkenyl boronates and alkenyl acetates can be employed for C-H bond alkenylation under Ru catalysis. Kakiuchi and coworkers demonstrated that aromatic ketones and 2-phenylpyridines undergo regioselective alkenylation effectively on treatment with alkenyl boronates [72] and alkenyl acetates [73], respectively (Scheme 18.72 and Scheme 18.73). 

Successful examples for C-H bond alkenylations employing terminal aUcynes have been very limited compared to those for internal alkynes, because of the high reactivity of acetylene sp C-H bonds. As a rare example, the authors reported that 2-arylpyridines and 2-arylimidazoles and aromatic imines undergo aUcenylation on treatment with terminal silylacetylenes (Scheme 18.80) [80]. 

The Ir-catalyzed version via path A was disclosed by the authors group. In the reaction of 1-naphthols, an [IrCl(cod)]2/PtBu3 catalyst system is effective for the C-H bond alkenylation at the peri position (Scheme 18.86) [85]. Recently, Shibata and coworkers [86] reported that aromatic ketones undergo ortho alkenylation in the presence of a cationic Ir catalyst. 

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