Nonenzymatic enantioselective monoacetylation of prochiral 2-protectedamino-2-alkyl-1,3-propanediols utilizing a chiral sulfonamide-Zn complex catalyst.
[structure: see text] Treatment of a chiral sulfonamide with Et(2)Zn gave quantitatively its Zn complex and then the structure was determined by X-ray crystallographic analysis. Reaction of prochiral N-Boc-2-amino-2-alkyl-1,3-propanediols with Ac(2)O in the presence of 5 mol % of chiral sulfonamide-Zn complex catalyst afforded the corresponding chiral monoacetyl products in 70-92% yields with 70-88% ee values. The proposed mechanism for the catalytic monoacetylation of a prochiral 1,3-propanediol was presented on the basis of CSI-MS analysis.
Honjo
Takashi
T
Graduate School of Pharmaceutical Sciences, The University of Tokushima, Sho-machi, Tokushima 770-8505, Japan.
Nakao
Michiyasu
M
Sano
Shigeki
S
Shiro
Motoo
M
Yamaguchi
Kentaro
K
Sei
Yoshihisa
Y
Nagao
Yoshimitsu
Y
D000107:Acetylation; D000478:Alkylation; D000588:Amines / Q000737:chemistry*; D002384:Catalysis; D008956:Models, Chemical; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry*; D011409:Propylene Glycols / Q000138:chemical synthesis*; D013237:Stereoisomerism; D013449:Sulfonamides / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
D000588:Amines; D009942:Organometallic Compounds; D011409:Propylene Glycols; D013449:Sulfonamides; D015032:Zinc