"Front Matter". In: Organosilanes in Radical Chemistry - Index of

Acyloxy Migration 131
Me3Si Ph
Si Ph
O
R
Me3Si Ph
Si Ph
O
R
R
Me3Si O
Si
Ph
O Si
Me3Si Ph
R Ph
52 53 54
SePh
55
1) slow addition (7h)
Bu 3SnH, AIBN, 80 �C
2) MeLi
R = Me
R = Ph
R
OH
Me3Si Ph
Si H
O
R
H
58
Ph
+
R
81%, 56:57 = 14:1
74%, 56:57 = 18:1
OH
56 57
Ph
(6.10)
(6.11)
The same methodological approach has been extended to the synthesis
of biaryls [24]. Reaction (6.12) shows a few examples in which the transfers
of functionalized aryl groups from silicon to aryl radicals are successful.
A mechanistic scheme similar to that reported in Reaction (6.10) has been
proposed.
X
R Si
O
Br
X
R = Ph
R = SiMe 2Ph
R = Me
6.3 ACYLOXY MIGRATION
1) slow addition (7h)
Bu 3SnH, AIBN
2) MeLi
X = H
X = F
X = OMe
OH
X
71%
49%
77%
(6.12)
The 1,2 migration of an acyloxy group in b-(acyloxy)alkyl radicals has been
the subject of numerous synthetic and mechanistic studies [25]. These