Aldimine rhodium-catalyzed arylation

Scheme 9.6 Rhodium-catalyzed direct arylation of aldimine 11 with boronic acid 10.

The rhodium-catalyzed alkylation has also been extended to the alkylation of a,P-unsaturated aldimines (Scheme 19.75) [109], An efficient system was found using [RhCl(coe)2]2 in combination with electron-rich Ugands (i.e., PCyj, FcPCyj), allowing milder reaction conditions (i.e., 50°C). Under these conditions, limited ( /Z)-isomerization was observed and the reaction proceeded with olefins substituted with alkyl, aryl, ester, and alkyne groups. 

The rhodium-catalyzed addition of aryl- and 1-alkenylboronic acids tooc, unsaiurated ketones, aldehydes, esters, and amides gave the conjugate 1,4-addition products in high yidds. The ifaodium(I) complexes also catalyzed the 1,2-addition of organoboronic acids to aldehydes or N-sulfonyl aldimines. The dficiency of protocol was demonstrated in the asymmetric addition reactions of organoboronic acids in the presoice of a rhodium(acacV BINAP complex. 

Guimond N, Fagnou K (2009) Isoquinoline synthesis via rhodium-catalyzed oxidative cross-coupling/cyclization of aryl aldimines and alkynes. J Am Chem Soc 131 12050-12051 Booth BL, CoUis A (1989) One-step synthesis of A -(l-benzylisoquinohn-3-yl)phenylacet-amidinium trifluoromethanesulphonate derivatives from phenylacetonitiiles and trifluoro-methanesulphonic Acid. J Chem Res Synop 304-305... 

Ishiyama and Hartwig disclosed a set of rhodium(I)-catalyzed intermolecular Heck-type reactions between aryl iodides and N-heterocyclic aldimines to form the corresponding ketimines. Ishiyama T, Hartwig J (2000) 122 12043... 

Ishiyama, T. and Hartwig, J.R (2000) A Heck-type reaction involving carbon-heteroatom double bonds. Rhodium(I)-catalyzed coupling of aryl halides with A-pyrazyl aldimines. J. Am. Chem. Soc., 122, 12043-4. 

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