Palladium-Catalyzed Trans-Selective Synthesis of Spirocyclic Cyclobutanes Using α,α-Dialkylcrotyl- and Allylhydrazones.
J Am Chem Soc
; 145(33): 18591-18597, 2023 Aug 23.
Article
in En
| MEDLINE
| ID: mdl-37552631
ABSTRACT
Herein, we demonstrate the use of E/Z mixtures of α,α-disubstituted crotylhydrazones to obtain spirocyclic vinylcyclobutanes in a diastereoselective fashion. We show 24 examples of a 1,1-insertion/4-exo-trig tandem process to produce these motifs. Additionally, spirocyclic alkylidene cyclobutanes can be obtained by using α,α-disubstituted allylated hydrazones (11 examples). In this study, we show that the aryl migrating group has a dramatic impact on the course of the reaction. Specifically, allylic C-H insertion products can be obtained in good yields using bromoenones as reaction partners. When Pd(0) is used with no aryl or alkenyl bromide, an intramolecular cyclopropanation reaction takes place to afford [2.1.0]-bicycles.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
J Am Chem Soc
Year:
2023
Document type:
Article
Affiliation country:
United States
Publication country:
EEUU
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ESTADOS UNIDOS
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ESTADOS UNIDOS DA AMERICA
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EUA
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UNITED STATES
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UNITED STATES OF AMERICA
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US
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USA