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whereas in the Mizoroki-Heck reaction such olefins are rare and often
require special protocols and ancillary ligands. The Fujiwara-Moritani
reaction has been applied to rather complex or challenging olefins, such as
a-methylenebutyrolactone,
341
cinnamylphosphonates,
342
b-substituted a,b-
unsaturated Weinreb amides,
343
Boc-protected allylamines
344
and others.
345
The reaction with allyl esters was reported by Liu and co-workers to afford
selectively the normal products formed by [PdH] elimination.
346
Kim and co-
workers described the stereoselective arylation of the trisubstituted alkene
bond in oxindole derivatives, which gave much better results than the
regular Mizoroki-Heck arylation of the same substrates by aryl iodides
(Scheme 9.112).
347
Intramolecular reactions can also be unambiguous, if alternative positions
are properly protected. Gaunt and co-workers developed a highly regiose-
lective procedure for the alkenylation of N-protected pyrroles using a peroxy
ester as a terminal oxidant - N-acylpyrroles underwent 2-alkenylation,
whereas N-trialkylsilyl-protected pyrroles gave 3-isomers.
348
This protocol in
an intramolecular version was used by the same group in the elegant syn-
thesis of important natural metabolite rhazinicine (Scheme 9.113).
349
Intramolecular alkenylation leading to the formation of quaternary carbon
atom was investigated in detail by Schiffner and Oestreich using anilides of
a,b-unsaturated acids.
350
A useful protocol remarkable for an unusually low
(for Fujiwara-Moritani reactions) palladium loading, using pyridine ligands
(pyridine itself or methyl nicotinate) was developed to afford the respective
indolin-2-ones, although substantial limitations are imposed on the anilides
used, which should be electron rich in both aromatic and alkene residues
(Scheme 9.114).
EtOOC
Ar
COOEt
Pd(OA c)
2,
AgOA c
PivOH, PhH, reflux, 24 h
O
O
Me
Me
Scheme 9.112 Arylation of a trisubstituted alkene residue (only the major stereo-
isomer is shown).
O
2
N
Pd(TFA )
2
(10 mol%)
t-BuOOCOPh
AcOH-dioxane-DMSO
70°C
NO
2
Me
3
Si
Me
3
Si
N
N
CO
2
R
O
RO
2
C
O
53%
Scheme 9.113
Intramolecular Fujiwara-Moritani reaction in the synthesis of im-
portant metabolites.
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