TY - JOUR
T1 - Examination of Diels-Alder/Tsuji-Trost Route towards Kopsia Alkaloids
AU - Zhigileva, Ekaterina A.
AU - Molchanova, Marina V.
AU - Solyev, Pavel N.
AU - Korlyukov, Alexander A.
AU - Baranov, Mikhail S.
AU - Mikhaylov, Andrey A.
N1 - Publisher Copyright:
© 2023 Georg Thieme Verlag. All rights reserved.
PY - 2023/9/4
Y1 - 2023/9/4
N2 - A reaction sequence of Diels Alder cycloaddition and Tsuji-Trost allylation was examined in terms of its application to the synthesis of kopsinine and the related Kopsia alkaloids. Results of the studies in two synthetic directions are presented herein: 1) synthesis of the properly substituted diene, required for the Diels Alder step; and 2) model studies and optimization of the key reaction sequence in the absence of side-chain. Details on the challenging introduction of the side-chain into tetrahydrocarboline ketone and its silylation, resulting in rare but unproductive vinylogous Claisen cyclization, and the successful Mannich/ Mukaiyama aldol sequence are disclosed in the first direction. In the second direction, the endo-selective Diels Alder reaction with allyl acrylate and Tsuji Trost allylation providing incorrect stereochemistry are disclosed. Interaction of both dienes with an alkyne provides carbazoles via Alder Rickert reaction.
AB - A reaction sequence of Diels Alder cycloaddition and Tsuji-Trost allylation was examined in terms of its application to the synthesis of kopsinine and the related Kopsia alkaloids. Results of the studies in two synthetic directions are presented herein: 1) synthesis of the properly substituted diene, required for the Diels Alder step; and 2) model studies and optimization of the key reaction sequence in the absence of side-chain. Details on the challenging introduction of the side-chain into tetrahydrocarboline ketone and its silylation, resulting in rare but unproductive vinylogous Claisen cyclization, and the successful Mannich/ Mukaiyama aldol sequence are disclosed in the first direction. In the second direction, the endo-selective Diels Alder reaction with allyl acrylate and Tsuji Trost allylation providing incorrect stereochemistry are disclosed. Interaction of both dienes with an alkyne provides carbazoles via Alder Rickert reaction.
UR - http://www.scopus.com/inward/record.url?scp=85174350812&partnerID=8YFLogxK
U2 - 10.1055/a-2186-7034
DO - 10.1055/a-2186-7034
M3 - Article
AN - SCOPUS:85174350812
SN - 0039-7881
VL - 56
SP - 346
EP - 356
JO - Synthesis
JF - Synthesis
IS - 2
ER -