Rhodium-catalysed arylation of aldehydes with arylstannanes

Abstract

Aryltrimethylstannanes react with aldehydes in the presence of a catalytic amount of a cationic rhodium complex, [Rh(cod)(MeCN) 2 ]BF 4 , affording the corresponding arylated secondary alcohols in good yields.

Rhodium-Catalyzed Addition of Organoboronic Acids to Aldehydes

“…[4] Notably, significant progress has been made toward stabilizing synthetic a-helical peptides through the incorporation of covalent or noncovalent linkages between constituent amino acid side chains. Examples include salt bridges, [5] lactams, [6] disulfide bridges, [7] hydrophobic interactions, [8] and metal ligation between natural [9] and unnatural amino acids.…”

“…The reaction may involve the transmetalation between arylboronic acid and the ROÀRh species (RO acac or OH) to give an ArÀRh I complex and the insertion of an aldehyde into the ArÀRh bond (Scheme 3). [4] The arylrhodium(i) complexes are unstable such as to preclude isolation in pure form, but they have been reasonably speculated to be the key intermediates in various coupling reactions with organic halides [9] and the addition to alkenes and alkynes. [10] However, the insertion of aldehydes into the carbon ± metal bond is very rare in transition metals except the allylic derivatives.…”

“…We previously demonstrated the efficiency of transmetalation between boron and palladium in the cross-coupling reaction of organoboron compounds with organic electrophiles [1] and the transmetalation between boron and rhodium in the catalytic 1,4-addition of aryl-or 1-alkenylboronic acids to enones.[2] An analogous addition reaction of organotin compounds to enones [3] and to aldehydes [4] has recently appeared. Here we report our first attempts to extend the protocol to the addition of aryl-and 1-alkenylboronic acids to aldehydes in an aqueous solution (Scheme 1).…”

Rhodium-catalyzed addition of arylboron compounds to nitriles, ketones, and imines

“…[Rh(OH)(cod)] 2 was prepared according to the published method [17]. 1 H and 13 C NMR spectra were recorded at 400 and 100 MHz, respectively, for CDCl 3 solutions. MS data were obtained by EI.…”

“…The rhodium-catalyzed nucleophilic addition reactions of organoboron and -stannane reagents to carbon-heteroatom multiple bonds are now recognized to be highly useful tools for C-C bond formation [1][2][3][4][5][6]. In these reactions, the mild, weakly nucleophilic organometallic reagents are effectively activated under rhodium catalysis to react readily with aldehydes and activated imines possessing electronwithdrawing groups, such as sulfonyl substituents, on their nitrogen (Scheme 1).…”