Diastereoselective Tin-Free Radical Reactions Jake Zimmerman, Department of Chemistry and Biochemistry, Ohio Northern University O
O
OH
X
X
H O
R1
H
OH R
single addition product
tandem addition product
O
O
X H
O
H
R
tin-free, silane-free, high yielding two C-C bonds formed products contain up to three contiguous stereocenters with good dr’s
1. R I Et3B (excess) 2. H2O2, NaOH
O 1 1. R I , Et3B
sequential addition product
R2
2.
(1 equiv) I, Et3B (excess)
O OH
3. H2O2, NaOH O
O
H
OH
second addition
R2 O
H
H
R1
first addition
Experiments focusing on the enantioselective variant of these methods are currently underway.
O
O CN
+
Et3B/O2, I
CN
RT, 30 min. O 0.25 g 0.50 g 1.00 g
O 95 %; dr: 2:1 97 %; dr: 2:1 95 %; dr: 2:1
tin-free minimal solvent no chromatography high yielding
