Enantioselective bromolactonization of conjugated (Z)-enynes.
A catalytic enantioselective syn-1,4-bromolactonization of conjugated (Z)-enynes was reported. Diastereomeric ratios >20:1 and up to 99% enantiomeric excesses were observed. Di-, tri-, and tetra-substituted bromoallenes were prepared together with lactone heterocycles efficiently and stereoselectively. Preliminary investigations suggest that the chiral catalyst may serve as a bifunctional reagent by interacting with both a carboxylic acid nucleophile and NBS electrophile.
Zhang
Wei
W
School of Pharmacy, University of Wisconsin, Madison, Wisconsin 53705, USA.
Zheng
Suqing
S
Liu
Na
N
Werness
Jenny B
JB
Guzei
Ilia A
IA
Tang
Weiping
W
D000466:Alkadienes / Q000737:chemistry; D000480:Alkynes / Q000737:chemistry*; D001966:Bromine / Q000737:chemistry*; D002384:Catalysis; D003432:Cross-Linking Reagents / Q000737:chemistry; D006571:Heterocyclic Compounds / Q000737:chemistry; D007783:Lactones / Q000737:chemistry*; D055620:Optical Phenomena; D013237:Stereoisomerism; D013379:Substrate Specificity
D000466:Alkadienes; D000480:Alkynes; D003432:Cross-Linking Reagents; D006571:Heterocyclic Compounds; D007783:Lactones; C025947:propadiene; D001966:Bromine