A total synthesis of ellipticine could be attained through the palladium catalyzed tandem cyclization-cross-coupling reaction of indolylborate (2 b) with vinyl bromide (3) as a key reaction.
known about the biological activities of these compounds. Six synthetic natural alkaloids and five of their derivatives were evaluated for their antiproliferative activity against HCT-116 and HL-60 cells. The activities of variants with the D-reduced ring or without the C(11)-Me group were lower than those of ellipticine. The conformer of guatambuine showed higher activities than guatambuine.
The palladium catalyzed cross-coupling reaction of trialky](indol-2-yl)borates with prop-2-ynyl carbonates was developed for the preparation of 2-allenylindole derivatives. When the reaction of indolyl-borates with tert-prop-2-ynyl carbonates was carried out. 2-allenylindoles were obtained solely. Otherwise, indolylborates reacted with sec-prop-2-ynyl carbonates, giving rise to 2-allenylindoles and/or 3-(prop-2-ynyl)indoles depending on the catalyst used. (C) 1998 Elsevier Science Ltd. All rights reserved.
A Concise Preparation of Yuehchukene and Its Analogues
The palladium catalyzed carbonylative cross-coupling reaction of indolylborates (2) with vinyl triflates (3) afforded indol-2-yl ketones (4), which were subsequently converted to hexahydroindeno[2,1-b]indoles (5) with the aid of an acid. This protocol was well adapted for the total synthesis of yuehchukene.
Application of the Pd-catalyzed heteroarylation to the synthesis of 5-(indol-2′-yl)pyridin-2-one and 5-(indol-2′-yl)pyran-2-one
The synthesis of 5-(indol-2'-yl)pyridin-2-ones and 5-(indol-2'-yl)pyran-2-one by Pd-catalyzed reactions is described. The best results are obtained using 2-indolylstannanes or 2-indolylzinc halides to be coupled with 5-bromopyridin-2-ones or 5-bromopyran-2-one in the presence of Pd(PPh3)(4) catalyst. Other Pd-catalyzed reactions are discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.
Total synthesis of yuehchukene could be realized through the palladium catalyzed carbonylative cross-coupling reaction of indolylborate (2 b) with cyclohexadienyl triflate (9) as a key reaction.