Significant Broadening of the Substrate Scope for the Hydrated Imidazoline Ring Expansion (HIRE) via the Use of Lithium Hexamethyldisilazide-Reference-Cited by-同舟云学术

Significant Broadening of the Substrate Scope for the Hydrated Imidazoline Ring Expansion (HIRE) via the Use of Lithium Hexamethyldisilazide

Published:2022-02-10 Issue:10 Volume:54 Page:2494-2510
ISSN:0039-7881
Container-title:Synthesis
language:en
Short-container-title:Synthesis

Author:

Krasavin Mikhail¹²^ORCID,Grintsevich Sergey¹,Sapegin Alexander¹

Affiliation:

1. Institute of Chemistry, Saint Petersburg State University

2. Immanuel Kant Baltic Federal University

Abstract

AbstractSubstrates that are insufficiently activated towards the hydrated imidazoline ring expansion (HIRE) process have been previously found to deliver exclusively the products of aminoalkyl side-chain ring expansion. Attempted reversal of the process by thermal activation towards HIRE failed. We have found that for such problematic substrates the HIRE-type ring expansion can be effectively achieved by applying lithium hexamethyldisilazide (LHMDS) in toluene. LHMDS is thought to promote intramolecular transamidation, which leads to ring-expanded 10- and 11-membered heterocyclic products in modest to good yields. The process significantly broadens the substrate scope amenable to the HIRE strategy.

Funder

Russian Science Foundation

Publisher

Georg Thieme Verlag KG

Subject

Organic Chemistry,Catalysis

Link

http://www.thieme-connect.de/products/ejournals/pdf/10.1055/s-0040-1719882.pdf

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