Phthalides by rhodium-catalyzed ketone hydroacylation.
Phthalides are biologically relevant five-membered lactones found in herbs, fruits, and vegetables. Herein we communicate the first atom-economical approach to phthalides by using enantioselective ketone hydroacylation. In the presence of Rh[(Duanphos)]X (X = NO(3), OTf, OMs), various 2-ketobenzaldehydes undergo intramolecular hydroacylation to produce phthalide products in good yields and 92-98% ee's. Our study highlights the key role counterions play in controlling both reactivity and enantioselectivity. A concise asymmetric total synthesis of the celery extract (S)-(-)-3-n-butylphthalide is also presented.
Phan
Diem H T
DH
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
Kim
Byoungmoo
B
Dong
Vy M
VM
D000215:Acylation; D002384:Catalysis; D010795:Phthalic Acids / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*
D010795:Phthalic Acids; D012238:Rhodium