Miura/Satoh group

T. Miura, K. Goto, H. Waragai, H. Matsumoto, Y. Hirose, M. Ohmae, H. Ishida, A. Satoh, and T. Inazu, Rapid oligosaccharide synthesis using a fluorous protective group, J. Org. Chem., 69 (2004) 5348-5353. 

Rhodium has been successfully used in a range of Suzuki-Miyaura type reactions. Satoh and Miura have reported the Suzuki-Miyaura-type cross-coupling of arylboron compounds with aryl halides in the presence of a rhodium-based catalyst system to produce the corresponding biaryls (Scheme 13.21). They also found, unexpectedly, that when employing benzonitrile as substrate under similar reaction conditions a multiple arylation is observed, in which nucleophilic arylation on the cyano group and subsequent ortho arylation via C-H bond cleavage is involved. 

Although there have been reports of thiophene vinylation using palladium catalysts, the requirement of acetic acid in the reaction mixture precludes the inclusion of many functional groups. In order to mitigate this, Satoh and Miura investigated... 

In order to find alternative routes to functimial olefins via the very useful Heck reaction [52] oxidative dehydrogenative cross-coupling of sp C-H bonds with (alkene) C-H bond was first discovered using Pd(II) catalyst and an oxidant, by Moritani and Fujiwara [25,53], This oxidative alkenylation of aromatic C-H bonds profitably performed using cheap and stable mthenium(ll) catalysts was shown for the first time in 2011 successively by the groups of Satoh and Miura [54], Ackermann [55], Bruneau and Dixneuf [56], and Jegaiunohan [57] [(Eq. 2)]. This Ru(n)-catalysed alkenylation reaction offers a potential to reach a large variety of functional alkenes at low cost and has been extended to annulation reactions with alkynes for a fast access to heterocycles. 

In 2009, Fagnou et al. discovered a Rh(III)-catalyzed synthesis of substituted isoquinolines 45 by oxidative annulation between N-tBu aromatic aldimines and internal alkynes [28a]. The -Bu leaving group was eliminated as isobutene in the reaction process and avoided the generation of a mixture of isoquinolines. However, the substrate scope was limited to aldimines, and a stoichiometric amount of Cu(0Ac)2-H20 was used as an external oxidant. Mechanistic studies omitted the ort/zo-alkenylation/64 -electrocyclization/oxidation pathway, and intermediate H2 was crucial for the C-N reductive elimination to proceed (Eq. (5.44)). At the same time, Satoh and Miura groups also exploited a Rh(III)-catalyzed oxidative cyclization of N-H benzophenone imine and internal alkynes to give isoquinolines [28b]. Both aromatic and aliphatic alkynes were agreeable for this protocol, but a stoichiometric amount of the Cu(II) salt was required. 

It is only very recently that rhodium-based catalytic systems have been described in efficient oxidative olefination reactions. Inspired by the work of Satoh and Miura on rhodium/copper-catalyzed aerobic oxidative coupling of benzoic acids with internal allqmes or acrylates (Scheme 9.11), Glorius and co-workers described, in 2012, a rhodium-catalyzed directing group assisted olefination of 2-aryloxazolines under air. This method, which necessitated rhodium, silver and copper metal sources, afforded the desired olefin-oxazoline products in moderate-to-good yields (Scheme 9.12). 

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