Regioselectivity carbonylation

Allenes undergo a Pd-catalyzed regioselective carbonylative heteroannulation with 2-iodothiophenols and carbon monoxide and this offers an attractive route to 3-methylene-thiochromanones 546 (Equation 198) <1999JOC9646>. 

In a second example of regioselective carbonylation, it was determined that monodentate ligands gave little reaction, while bidentate ligands dramatically increased the rate of the reaction [79]. Thus, in the preparation of an intermediate fragment of the PDEIV inhibitor 225, the carbonylation of 60 could be effected to afford the desired 440. This compound could then be carried forward to produce 224, used in preparing the analog 225. 

Lactone derivatives with formulae Co2(CO)6(/i-CO)(RC2R COO), with the ligands bound to the metals only through a carbon atom, are obtained upon regioselective carbonylation of coordinated alkynes (a) G. Palyi, G. Varadi, A. Visi-Orosz and L. Marko, J. Organomet. 

Yamamoto, H. and Maruoka, K. (1981) Regioselective carbonyl amination using diisobuty-laluminum hydride. Journal of the American Chemical Society, 103, 4186 194. 

Carbonylation proceeds in the presence of chalcogen compounds without poisoning Pd catalysts. Pd-catalyzed stereo- and regioselective carbonylative double thiolation of 1-octyne with diphenyl disulfide (3) afforded the (Z)-j6-(phenylthio)--unsaturated thioester 4 [2], The thioester 4 can be converted to 3-(phenylthio)-2-alkenal 5 by Pd-catalyzed reduction with HSnBu3 under mild conditions [3]. When propargyl alcohol was subjected to the carbonylation in the presence of either diphenyl diselenide (6) or disulfide 3, 3-phenylselenobutenolide 7 or 3-phenylthiobutenolide was obtained. The transformation involves isomerization of the acylpalladium intermediate 8 to 9 [4]. 

Although Pd-N complexes sometimes have catalytic activities that are comparable to that of the Pd-P complexes,they often lead to significantly different reactivity profiles as exemplified by the Pd-catalyzed regioselective carbonylation (Scheme 9) or the selective activation of a switchable bisnucleophile (Scheme 10). Other examples can be found in the catalytic hydrogenation of alkenes, or the carbacyclization of enynes, as well as in cross-coupling and allylic substitution reactions. ... 

T, Sakakura, M. Tanaka - Efficient Catalytic C-H Activation of Alkanes Regioselective Carbonylation of the Terminal Methyl Group of n-Pentane by [RhCl(CO)(PMe3)2], J. Chem. Soc., Chem. Commun., 758,1987. 

The preparation of bis (r 3-aiiyi)iron(II) complexes of the type [Fe(ri3-C3H5)2(PMe3)2] has been reported and their reactions with 1,3-dienes to form a mixture of products were described. The reaction of allyl halides with salts of [Fe(CO)3(NO)]- afforded [PeCli -allyl)(CO)2(NO)] complexes, which on treatment with l,2-bis(diphenylphosphino)ethane gave P,Y-unsaturated acyl iron complexes in good yields via regioselective carbonylation with retention of configuration of the allylic double bond. The same [Fe(Ti3-allyl)(CO)2(NO)] complexes were... 

Alper and coworkers have reported that the combination of BF3 OEt2 and cobalt complex (136) catalyzes the regioselective carbonylation of epoxides to the corresponding p-lactones (137) (Equation 83) [86]. Under this manifold, carbonylation of trans related aziridine (138) resulted in the inversion of stereochemistry, thus giving cis aziridine (139) (Equation 84) [86]. 

Relatively mild conditions suffice for the regioselective carbonylation (eq 12) and carboxylation of epoxides (eq 13). The... 

Xiao WJ, Alper H (1999) regioselective carbonylative heteioannulation of o-iodothiophenols with allenes and carbon monoxide catalyzed by a palladium complex A novel and efficient access to thiochroman-4-one derivatives. J Org Chem 64 9646-9652... 

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