TY - JOUR
T1 - Dearomatization of 3-cyanoindoles by (3 + 2) cycloaddition
T2 - From batch to flow chemistry
AU - Manneveau, Maxime
AU - Tanii, Saori
AU - Gens, Fanny
AU - Legros, Julien
AU - Chataigner, Isabelle
N1 - Funding Information:
This last observation was supported by in-line infrared analysis of the reaction mixture. 2d is characterized by absorption bands at 1429 cm−1 and 977 cm−1, probably corresponding to the reactive olefinic C2vC3 double bond. On the other hand, 1 features signals at 1067 cm−1 and 1249 cm−1, possibly corresponding to the CH3–O–CH2 and Si–CH3 fragments. These latters disappear while adding TFA to the reaction mixture. Alongside, bands at 1406 cm−1 and 1200 cm−1, illustrating the formation of cycloadduct 3d, appear once the TFA is added dropwise. The intensity of these signals is almost at its maximum at the end of the TFA addition, suggesting that the desired product 3d was nearly entirely formed.
Publisher Copyright:
This journal is © The Royal Society of Chemistry.
PY - 2020/5/14
Y1 - 2020/5/14
N2 - 1,3-Dipolar dearomatizing cycloadditions between a non-stabilized azomethine ylide and 3-cyanoindoles or benzofuran afford the corresponding 3D-heterocycles bearing a quaternary carbon centre at the ring junction. While 6 equivalents of ylide precursor 1 are required for full conversion in a classical flask, working under flow conditions limits the excess (3 equiv., tR = 1 min) and leads to a cleaner process, affording cycloadducts that are easier to isolate.
AB - 1,3-Dipolar dearomatizing cycloadditions between a non-stabilized azomethine ylide and 3-cyanoindoles or benzofuran afford the corresponding 3D-heterocycles bearing a quaternary carbon centre at the ring junction. While 6 equivalents of ylide precursor 1 are required for full conversion in a classical flask, working under flow conditions limits the excess (3 equiv., tR = 1 min) and leads to a cleaner process, affording cycloadducts that are easier to isolate.
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U2 - 10.1039/d0ob00582g
DO - 10.1039/d0ob00582g
M3 - Article
C2 - 32347286
AN - SCOPUS:85084692817
VL - 18
SP - 3481
EP - 3486
JO - Organic and Biomolecular Chemistry
JF - Organic and Biomolecular Chemistry
SN - 1477-0520
IS - 18
ER -