Diarylmethanols, formation

Obviously, this rhodium-catalyzed diarylmethanol formation with boronic acids still requires significant optimization in order to be competitive with the forementioned existing methodology using phenylzinc reagents, but these early results appear particularly promising. 

Electrophilic substitution of phenones. The facile formation of C,0-dilithiated diarylmethanols from diaryl ketones and LN, coupled with subsequent reaction with various electrophiles, " solves the compatibility problem of the conventional addition reaction with functional nucleophiles to prepare diaryl r-carbinols. 

Krug and Hartwig recently reported that arylrhodium(I) complex 317 imderwent insertion of benzaldehyde into the aryl-Rh bond to give a rhodium alkoxide intermediate, which led to the formation of either ketone 318 or diarylmethanol 319, depending on the reaction conditions. Ketone 318 was formed under nonaqueous conditions, whereas diarylmethanol 319 was formed under aqueous conditions. This type of insertion reaction is limited to aryl aldehydes. 

The first rhodium-catalyzed enantioselective arylation was described by Miyaura in 1998 (Scheme 8.5) [13]. The reaction between 1-naphthaldehyde (13) and phenylboronic acid (14) was catalyzed by a rhodium complex of the monodentate phosphine fSj-MeO-MOP (15), and resulted in the formation of diarylmethanol... 

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