Rhodium oxanorbornenes

Murakami [27] and Lautens [28] independently reported the rhodium-catalyzed addition of arylboronic acids to oxanorbornenes (Scheme 3.12). Murakami reported that the reaction of oxabenzonorbornadiene 37 a with phenylboronic acid 2m, in the presence of a rhodium-P(OEt)3 catalyst in MeOH at reflux, gave an 86% yield of the ring-opened alcohol 38 am. Lautens reported the asymmetric version of the reaction, where high enantioselectivity was observed with chiral ferrocenylbisphosphine hgand 39 in a... 

Scheme 3.12 Rhodium-catalyzed asymmetric addition of phenylboronic acid to oxanorbornenes [27, 28].

Scheme4.2S Proposed catalytic cycle for the rhodium

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