Rhodium(I)‐Catalyzed Intramolecular Carbonylative [2+2+1] Cycloadditions and Cycloisomerizations of Bis(sulfonylallene)s

Abstract

Novel [{RhCl(CO)dppp}(2)]-catalyzed intramolecular carbonylative [2+2+1] cycloadditions of bis(phenylsulfonylallene) derivatives under CO, leading to the facile formation of bis(phenylsulfonyl)bicyclo[n.3.0] frameworks (n=4-6), have been developed. The terminal double bonds of both allenyl moieties served exclusively as the two pi-components. In particular, this newly developed method was shown to be a powerful tool for the construction of bicyclo[6.3.0]undecadienones, which have hardly been prepared by the known Pauson-Khand (-type) reactions. The bicyclo[7.3.0]dodecadienone homologue (one extra carbon) could be formed in rather low yields. Alternatively, novel cycloisomerizations of bis(phenylsulfonylallene) derivatives with catalysis by the same Rh(I) complex under N(2) readily produced the 3,4-dimethylene-2,5-bis(phenylsulfonyl)cyclononene and the corresponding cyclooctene and cycloheptene frameworks.

Creation of Novel Cyclization Methods Using <i>sp</i>-Hybridized Carbon Units and Syntheses of Bioactive Compounds

“…Thus our next efforts were directed toward Rh I -catalyzed [2+2+1] carbonylative cycloaddition of bisallenes. [18][19][20] The initial attempt was performed by treatment of bisallenes 25 with a catalytic amount of [RhCl(CO) 2 ] 2 or [RhCl(CO) dppp] 2 to afford the bicyclo [5.3.0] decadienones 26 in high yields. The largersized eight-membered bicyclo[6.3.0] undecadienones 28 were obtained from 27 in satisfactory-to-high yields.…”

“…The largersized eight-membered bicyclo[6.3.0] undecadienones 28 were obtained from 27 in satisfactory-to-high yields. [18][19][20] A more complicated tricyclic (6/8/5) compound was prepared by this method. 21) Furthermore, it would become interesting to see whether construction of the nine-membered bicyclo [7.3.0]-dodecadienone skeletons 30 20) would be possible using this method.…”

“…[18][19][20] A more complicated tricyclic (6/8/5) compound was prepared by this method. 21) Furthermore, it would become interesting to see whether construction of the nine-membered bicyclo [7.3.0]-dodecadienone skeletons 30 20) would be possible using this method. The bisallene 29 was exposed to Rh I -catalyst in refluxing xylene to give the desired 30 in a rather low yield (33%) along with the nine-membered monocyclic compound 31 possessing a bis(exo-methylene) group (17%).…”

“…Exclusive formation of 31 was realized when 29 was exposed to Rh Icatalyzed conditions under N 2 atmosphere instead of CO to furnish 31 in 96% yield. 20) The common intermediate C would be considered for the production of both 30 and 31 (Chart 7). The thus formed monocyclic compound 31 subsequently underwent [4+2]-type cycloaddition with suitable dienophiles 22) resulting in the formation of bicyclo[m. 4.0] derivatives 32 in high yields (Chart 7).…”

Rh(I)-Catalyzed Intramolecular Carbonylative [2+2+1] Cycloaddition Reaction: Preparation of Bicyclo[5.3.0]decadienones with Substituted Cyclopentenone Frameworks

“…9,10) of enynes (alkyne-alkene). [11][12][13][14][15][16][17] Furthermore, the PKTR of the bis(allene) s 1 (n=1,2) has become a powerful tool for constructing not only the bicyclo[5.3.0]-decadienones 2 (n=1), but also the larger-sized bicyclo[6.3.0]-undecadienone skeletons 2 (n=2) in satisfactory to high yields [18][19][20] (Chart 1). This ring-closing reaction has exclusively occurred at both terminal double bonds of the allenic moieties of 1 (n=1, 2).…”