UPDATES
Palladium-Catalyzed Alkene Carboamination Reactions
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and N-trifluoroacetyl protecting groups. Although
diastereoselectivities are typically modest, chemical
yields are generally good, and this represents a useful
expansion in the scope of alkene carboamination
methodology. Future work will be directed towards
the development of enantioselective variants of these
transformations.
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Experimental Section
General Procedure for Pd-Catalyzed Carboamination
Reactions
An oven-dried test tube equipped with a magnetic stirbar
and a rubber septum was cooled under a stream of nitrogen
and charged with Pd(OAc)2 (2 mol%), CPhos or RuPhos
(5 mol%), and LiO-t-Bu (1.4 equiv.). The tube was purged
with nitrogen and then a solution of the aryl triflate
(1.2 equiv.) in CF3Ph (1 mL) was added and the resulting
mixture was stirred at room temperature for 1 min. A solu-
tion of the N-protected amine substrate (1 equiv.) in CF3Ph
(1.5 mL) was added, and the mixture was heated to 1008C
for 15 h. The mixture was then cooled to room temperature,
saturated aqueous NH4Cl (2 mL) was added, the organic
layer was removed, and the aqueous layer was extracted
with dichloromethane (42 mL). The combined organic
layers were dried over anhydrous Na2SO4, filtered, and con-
centrated under vacuum. The crude product was then puri-
fied via flash chromatography.
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[11] Our prior studies have shown factors that facilitate gen-
eration of cationic palladium intermediates (such as
polar solvents, non-coordinating triflate ligands, and
electron-rich phosphine ligands) promote the anti-ami-
nopalladation pathway. See ref.[8]
Acknowledgements
The authors thank the NIH-NIGMS (GM071650) for finan-
cial support of this work.
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2932–2935.
[13] We have previously described the conversion of non-
racemic 12 to (+)-aphanorphine via cleavage of the N-
tosyl group, N-methylation, and O-demethylation. See
ref.[12]
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À
that proceed via C H functionalization of solvent fol-
Adv. Synth. Catal. 2015, 357, 2339 – 2344
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