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Diastereoselective Synthesis of N ‐Substituted Planar Chiral Ferrocenes Using a Proline Hydantoin‐Derived Auxiliary
Author(s) -
Metallinos Costa,
John Joshni,
Zaifman Josh,
Emberson Kassandra
Publication year - 2012
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.201100862
Subject(s) - chemistry , hydantoin , electrophile , proline , moiety , ferrocene , reagent , planar chirality , lithium (medication) , electrophilic substitution , chiral auxiliary , stereochemistry , combinatorial chemistry , organic chemistry , enantioselective synthesis , amino acid , catalysis , medicine , biochemistry , electrode , endocrinology , electrochemistry
An N ‐substituted ferrocene bearing a proline‐derived chiral directing group undergoes diastereoselective lithiation–electrophile quench to give planar chiral products in >95:5 dr . The starting material is synthesized by imidation of iodoferrocene with L ‐proline hydantoin, followed by hydrosilylation. Although the auxiliary is stable to lithium bases of the types RLi and R 2 NLi, the ortho ‐substituted products may be converted to solely planar chiral derivatives with simple reagents thanks to a labile triethylsilyloxy moiety.