Iron-Catalyzed Cross-Coupling of 1-Alkynylcyclopropyl Tosylates and Related Substrates
作者:Daniel J. Tindall、Helga Krause、Alois Fürstner
DOI:10.1002/adsc.201600357
日期:2016.7.28
1‐Alkynylcyclopropyl tosylates react with alkylmagnesium halides in the presence of catalytic ferric acetylacetonate [Fe(acac)3] under net propargylic substitution; allene formation, which is the prevalent reactivity mode of propargylic substrates otherwise, was noticed as a side reaction only when branched alkyl‐ or aryl‐Grignard reagents were used. These transformations represent the first successful iron‐catalyzed
Diastereoselective titanium-mediated construction of cis-2,3-ring annelated 1-(2′-chloroethyl)cyclopropanols
作者:Frédéric Lecornué、Jean Ollivier
DOI:10.1039/b211642a
日期:——
Titanium(IV)-mediated cyclopropanation induced by reaction of cycloalkylmagnesium bromides 1a-e in the presence of titanium tetraisopropoxide with ethyl beta-chloropropionate 2 yielded cis-fused 1-(2'-chloroethyl)cyclopropanols 3b-e with diastereoselectivity highly depending on the ring size. Unexpected rearrangementproducts 5d,e were isolated in some cases.