Donör-Akseptör Siklopropanların N-Metil İndol ile Gd(OTf)3 Katalizli Nükleofilik Halka Açılması

Öz

Bu çalışmada, N-metil indolün çeşitli donör-akseptör (DA) siklopropanlarla olan homo-Michael katılması Gd(OTf)₃ katalizörlüğünde gerçekleştirilmiştir. Reaksiyonda, yüksek basınç ve yüksek katalizör oranına gerek duyulmamıştır. Substrat olarak kullanılan DA siklopropanların tümü, yapılarına bağlı olmaksızın geliştirilen optimize metot şartlarında yüksek reaktivite göstermişlerdir. Bu sebepten dolayı, benzeri çalışmalar için literatürde ihtiyaç duyulan ılıman şartlara bir yenisi daha eklenmiştir. Sentezi gerçekleştirilen bileşiklerin yapı karakterizasyonu, ¹H, ¹³C NMR ve Yüksek Çözünürlüklü Kütle Spektroskopisi (HRMS) vasıtasıyla gerçekleştirilmiştir.

Anahtar Kelimeler

• Donör-akseptör siklopropan,indol,homo-Michael

Gd(OTf)3 Catalyzed Nucleophilic Ring Opening of Donor-Acceptor Cyclopropanes with N-Methyl Indole

Öz

In this study, homo-Michael addition of N-methyl indole into various donor-acceptor (DA) cyclopropanes was performed using Gd(OTf)₃ as a catalyst. In the reaction, high pressure and high catalyst ratio were not required. All of the DA cyclopropanes used as substrates showed high reactivity without regard to their structure under optimizing method conditions. For this reason, a new one is added to the mild conditions required in the literature for similar studies. The structure characterization of the synthesized compounds was carried out by ¹H, ¹³C NMR and High Resolution Mass Spectroscopy (HRMS).

Anahtar Kelimeler

• Donor-acceptor cyclopropane,indole,homo-Michael

Kaynakça

1. Chang F, Lin L, Xia Y, Zhang H, Dong S, Liu X, Feng X 2018. Chiral N, N′‐dioxide/ScΙΙΙ complex‐catalyzed asymmetric ring‐opening reaction of cyclopropyl ketones with indoles. Advanced Synthesis & Catalysis, 360 (14): 2608-2612.
2. Dulin CC, Murphy KL, Nolin KA 2014. Calcium-catalyzed Friedel–Crafts addition of 1-methylindole to activated cyclopropanes. Tetrahedron Letters, 55 (38): 5280-5282.
3. Budynina EM, Ivanov KL, Sorokin ID, Melnikov MY 2017. Ring opening of donor–acceptor cyclopropanes with N-nucleophiles. Synthesis, 49 (14): 3035-3068.
4. Harrington P, Kerr MA 1997. The high pressure reaction of cyclopropanes with indoles catalyzed by ytterbium triflate. Tetrahedron Letters, 38 (34): 5949-5952.
5. Richmond E, Vukovic VD, Moran J 2018. Nucleophilic ring opening of Donor–Acceptor cyclopropanes catalyzed by a Brønsted Acid in hexafluoroisopropanol. Organic Letters, 20 (3): 574-577.
6. Schneider TF, Kaschel J, Werz DB 2014. A new golden age for donor–acceptor cyclopropanes. Angewandte Chemie International Edition, 53 (22): 5504-5523.
7. Talukdar R, Saha A, Tiwari DP, Ghorai MK 2016. Ring opening of DA-cyclopropanes with electron rich arene/heteroarene: synthesis of 2-(2,2-diarylethyl) malonates. Tetrahedron, 72 (5): 613-624.
8. Tejeda JEC, Landschoot BK, Kerr MA 2016. Radical cyclizations for the synthesis of syrroloindoles: Progress toward the Flinderoles. Organic Letters, 18 (9): 2142-2145.

9. Wales SM, Walker MM, Johnson JS 2013. Asymmetric Synthesis of Indole Homo-Michael Adducts via Dynamic Kinetic Friedel–Crafts Alkylation with Cyclopropanes. Organic Letters, 15 (10): 2558-2561.