A straightforward synthesis of ecteinascidin 743 was accomplished from readily available l-glutamic acid as a single chiral source. Our novel synthesis features a concise and convergent approach for construction of the B-ring, consisting of a sequence involving a stereoselective Heck reaction between a diazonium salt and an enamide, oxidative cleavage of the resulting alkene, and intramolecular ortho substitution of the phenol by an aldehyde.

Cyanoformate esters add across 1,2-dienes in the presence of a nickel/PMe(2)Ph catalyst to afford beta-cyano-alpha-methylenealkanoates regioselectively, which are kinetically favored and readily isomerize to thermodynamically favored alpha-cyanomethyl-alpha,beta-unsaturated carboxylates at high temperature under the nickel catalysis, possibly through oxidative addition of the C-CN bond. Similar cyanoesterification products are produced from chloroformate esters, trimethylsilyl cyanide, and 1,2-dienes in the presence of a nickel/dppp catalyst. The resulting cyanoesterification products have a structure of allylic cyanide and thus undergo further allyl cyanation reaction across alkynes with the aid of a nickel/P(4-CF(3)-C(6)H(4))(3) catalyst to afford highly substituted acrylonitrile derivatives.

Average void fraction α Macro scales Λl, Λg (cm) Open symbols: longitudinal Λl Solid symbols: lateral Λg 0.45

No abstract

Conversion of readily available vindoline to 11-mesyloxytabersonine, a versatile synthetic intermediate for indole alkaloids, has been achieved by a 9-step sequence in 39% overall yield.Key words alkaloid; indole; natural product; vindoline; tabersonineThe aspidosperma-type indole alkaloids comprise one of the largest groups of indole alkaloids, with more than 250 compounds isolated from a variety of biological sources.

Carboxylic acid esters P 0360 Cyanoesterification of 1,2-Dienes Catalyzed by Nickel. -In extension of previously published results a three-component cyanoesterification of allenes is presented. -(HIRATA, Y.; INUI, T.; NAKAO*, Y.; HIYAMA, T.; J. Am. Chem. Soc. 131 (2009) 18, 6624-6631; Dep. Mater. Chem., Grad. Sch. Eng., Kyoto Univ., Nishikyo, Kyoto 615, Japan; Eng.) -Nuesgen 37-050

Supporting Information, pages S40 and S42. The 1 H NMR spectra of compounds 21 and 22, respectively, were improperly manipulated in the originally published Supporting Information to obscure small peaks corresponding to solvent and other impurities. Unaltered spectra are included in the revised Supporting Information.The changes do not affect any of the conclusions of the article. ■ ASSOCIATED CONTENT* S Supporting Information Experimental details, characterization data, and NMR spectra (revised). This material is available free of charge via the Internet at http://pubs.acs.org.