Premium
Enantioselective Construction of Spirooxindole‐Fused Cyclopenta[ c ]chromen‐4‐ones Bearing Five Contiguous Stereocenters via a Stepwise (3+2) Cycloaddition
Author(s) -
Vagh Sandip Sambhaji,
Karanam Praneeth,
Liao ChengChieh,
Lin TingHan,
Liou YanCheng,
Edukondalu Athukuri,
Chen YiRu,
Lin Wenwei
Publication year - 2020
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.201901655
Subject(s) - stereocenter , enantioselective synthesis , oxindole , chemistry , bifunctional , cycloaddition , electrophile , stereochemistry , combinatorial chemistry , catalysis , organic chemistry
The bifunctional quinine‐catalyzed stepwise (3+2) cycloaddition for the enantioselective construction of spirooxindole‐fused cyclopenta[ c ]chromen‐4‐ones is developed. The reactions of 3‐homoacylcoumarins and alkylidene oxindole electrophiles generate aforementioned spirooxindole‐chromenone adducts bearing five contiguous stereocenters, of which one is the spiro all‐carbon quaternary stereocenter in high yields (up to 99%) with excellent stereoselectivities (up to >20:1 dr and 99% ee). This methodology was investigated for three different alkylidene oxindole electrophiles and could also be practically demonstrated on a gram scale. Mechanistic investigations revealed that the (3+2) cycloaddition for the enantioselective synthesis of spirooxindole‐fused cyclopenta[ c ]chromen‐4‐ones is proceeding via a stepwise reaction pathway.