Catalytic regioselective sulfonylation of alpha-chelatable alcohols: scope and mechanistic insight.
This paper describes a convenient protocol for the regioselective sulfonylation of alpha-chelatable alcohols. Typically, the reaction of alpha-heterosubstituted alcohols with 1 equiv of p-TsCl and 1 equiv of Et(3)N in the presence of 2 mol % of Bu(2)SnO leads to rapid, regioselective, and exclusive monotosylation. The pK(a) of the amine was correlated to the reaction rate. A plausible mechanism for this reaction has been proposed on the basis of (119)Sn NMR studies.
Martinelli
Michael J
MJ
Chemical Process R&D, Lilly Research Laboratories, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, Indiana 46285-4813, USA. mjm@lilly.com
Vaidyanathan
Rajappa
R
Pawlak
Joseph M
JM
Nayyar
Naresh K
NK
Dhokte
Ulhas P
UP
Doecke
Christopher W
CW
Zollars
Lisa M H
LM
Moher
Eric D
ED
Khau
Vien Van
VV
Kosmrlj
Berta
B