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Highly Enantioselective Michael Additions of Isobutyraldehyde to Nitroalkenes Promoted by Amphiphilic Bifunctional Primary Amine‐Thioureas in Organic or Aqueous Medium
Author(s) -
Ma ZhiWei,
Liu YuXia,
Zhang WenJing,
Tao Yan,
Zhu Yu,
Tao JingChao,
Tang MingSheng
Publication year - 2011
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201101086
Subject(s) - isobutyraldehyde , chemistry , bifunctional , thiourea , michael reaction , enantioselective synthesis , organic chemistry , amine gas treating , amphiphile , aqueous solution , enantiomer , primary (astronomy) , combinatorial chemistry , organocatalysis , catalysis , physics , astronomy , copolymer , polymer
A novel class of chiral amphiphilic bifunctional thioureas based on a beyerane scaffold and each containing a primary amino group were designed and synthesized from the readily available natural product isosteviol. The thioureas were shown to be effective for catalyzing asymmetric Michael additions between isobutyraldehyde and nitroalkenes. The chiral thiourea 1a furnished S enantiomers, whereas 1b afforded R enantiomers, both with high yields (up to 92 %) and high to excellent enantioselectivities (up to 98 %). Furthermore, the reactions proceeded smoothly both in organic solvents and in water under mild conditions.