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Regioselective and Enantiospecific Synthesis of Dioxepines by (Cyclopentadienyl)ruthenium‐Catalyzed Condensations of Diazocarbonyls and Oxetanes
Author(s) -
Egger Léo,
Guénée Laure,
Bürgi Thomas,
Lacour Jérôme
Publication year - 2017
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201700638
Subject(s) - regioselectivity , ruthenium , cyclopentadienyl complex , chemistry , catalysis , diazo , stereochemistry , medicinal chemistry , decomposition , organic chemistry
Abstract 1,4‐Dioxepines result from the decomposition of α‐diazo‐β‐keto esters in the presence of oxetanes using the catalytic combination of the (cyclopentadienyl)ruthenium complex [CpRu(CH 3 CN) 3 ][BAr F ] and 1,10‐phenanthroline. The regioselective [4+3] insertions follow an S N 1‐like mechanism and occur yet enantiospecifically ( es 74%). The retention of configuration was ascertained by vibrational circular dichroism (VCD) and solid state analyses. Furans, products of [4+1] insertions, are only observed as traces in the above protocol. To promote their formation under CpRu catalysis, it is necessary to use a two‐step process with γ‐halogenated alcohols as substrates.