Premium
Direct Metal‐Free Entry to Aminocyclobutenes or Aminocyclobutenols from Ynamides: Synthetic Applications
Author(s) -
Alcaide Benito,
Almendros Pedro,
LázaroMilla Carlos
Publication year - 2016
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201601044
Subject(s) - chemistry , reagent , cycloaddition , catalysis , hydroxylation , reactivity (psychology) , ring (chemistry) , metal , organic chemistry , combinatorial chemistry , medicinal chemistry , medicine , alternative medicine , pathology , enzyme
The [2+2] cycloaddition of ynamides with the highly polarized reagent Tf 2 C=CH 2 has been developed to regioselectively afford bis(triflyl)aminocyclobutenes in the absence of catalyst under mild conditions. Incidentally, with the ynamides bearing electron‐rich aromatic rings at the C‐terminal, an interesting reactivity switch was observed; a cyclization/hydroxylation sequence yielded 2‐amino‐3‐(triflyl)cyclobut‐2‐enols. Aminocyclobutene construction with addition of alcohols resulted in the formation of aminocyclobutenyl ethers through a cyclization/hydroalkoxylation process. Moreover, the utility of functionalized aminocyclobutenes as precursors for further elaboration was demonstrated with the preparation of α‐amino‐β,γ‐unsaturated ketones and 3‐(triflyl)buta‐1,3‐dien‐2‐amines through 4 π‐electrocyclic ring opening.