Ligand-induced reactivity of β-diketiminate magnesium complexes for regioselective functionalization of fluoroarenes: Via C-H or C-F bond activations

Article abstract of DOI:10.1039/c7cc07193k

Using β-diketiminate Mg(ii) complexes containing either alkyl, aryl or amide groups, the regioselective functionalization of a wide range of fluoroarenes is accomplished but in uniquely different ways. Overcoming common limitations of traditional s-block bases, kinetically activated [(^DippNacnac)Mg(TMP)] (1) deprotonates these molecules at room temperature, trapping sensitive fluoroaryl anions that can then engage in Negishi cross-coupling; whereas [(^DippNacnac)Mg(R)THF] (R = ⁿBu, Ph, benzofuryl) have proved to be effective reagents for C-F bond alkylation/arylation via pyridine directed C-F bond cleavage.

Full text of DOI:10.1039/c7cc07193k

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Marilyn M. Olmstead, Alan L. Balch, Josep M. Poblet, Luis Echegoyenet al.
Reactivity differences of Sc
first methanofullerene derivatives of Sc
3
N@C2n (2n
=
68 and 80). Synthesis of the
3
N@D5h-C80
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Ligand-induced reactivity of β-diketiminate magnesium
complexes for regioselective functionalization of fluoroarenes via
C-H or C-F bond activations
Received 00th January 20xx,
Accepted 00th January 20xx
DOI: 10.1039/x0xx00000x
www.rsc.org/
*
Laia Davin, Ross McLellan, Alan R. Kennedy and Eva Hevia
Using β-diketiminate Mg(II) complexes containing either alkyl, aryl reagents can undergo coupling reactions via C-F bond
or amide groups, the regioselective functionalization of a wide activation.
9
range of fluoroarenes is accomplished but in uniquely different Exploiting ligand-ligand cooperation by combining a sterically
ways. Overcoming common limitations of traditional s-block operative
Dipp
β
(1) basic TMP amide group, we recently reported the
-diketiminate ligand with a kinetically-activated
bases,
kinetically
activated
[( Nacnac)Mg(TMP)]
deprotonates these molecules at room temperature, trapping regioselective magnesiation of a range of N-heterocyclic
sensitive fluoroaryl anions that can then engage in Negishi cross- molecules such as diazines and 1,3-benzoazoles using
Dipp
n
Dipp
Dipp
couplings; whereas [( Nacnac)Mg(R)THF] (R= Bu, Ph, [( Nacnac)Mg(TMP)]
(1)
(
Nacnac
; TMP = 2,2,6,6-
tetramethylpiperidide) (Figure 1). While the -diketiminate
=
i
benzofuryl) have proved to be effective reagents for C-F bond Ar*NC(Me)CHC(Me)NAr*; Ar* = 2,6- Pr
2
6 3
-C H
1
0
alkylation/arylation via pyridine directed C-F bond cleavage.
β
ligand acts as a spectator in the metallation step, it plays a
major role facilitating the trapping and stabilization of the
newly formed sensitive heterocyclic anions. The kinetic basicity
of the TMP ligand is best illustrated when comparing the
Fluoroarene molecules represent one of the most prevalent
entities within biologically active and pharmaceutical
1
compounds. The regioselective manipulation of such
significant synthetic building blocks is therefore of paramount
importance in the quest for efficient molecular design
strategies, especially as naturally occurring fluoroarenes are
reactivites of
Dipp
1 with those observed for the n-butyl analogue
n
Nacnac)Mg( Bu)THF] (2), which in most cases only forms
[(
coordination adducts with these N-heterocyclic substrates.
During these studies the substituted pyridine 2-(2,4-
2
exceptionally rare. Two powerful methods in this regard are
3
metallation, that is, a C-H – C-M conversion, and C-F
difluorophenyl)pyridine
(
ppf
)
was also regioselectively
4
activation. The latter has predominantly been investigated
10a
metallated ortho to both fluorine substituents,
without
5
using precious transition metal complexes, using carefully
observing decomposition at room temperature of the
designed systems that favour C-F activation over competing C-
6
H activation processes. Main group activity in C-F activation is
metallated intermediate, hinting at the potential of
Dipp
[(
Nacnac)Mg(TMP)] (1) to promote Mg-H exchange
much rarer, though though it has been recently shown that
low valent Mg(I), Si(II) or Al(I) complexes can also
regioselectively promote oxidative addition of fluoroarene C-F
processes for fluorinated aromatic molecules.
Ar*
Ar*
iPr
N
N
N
N
Bu
Mg TMP
Mg
7
Ar* =
bonds.
THF
Ar*
Ar*
iPr
Deprotonative metallation by organolithium reagents is
1
2
particularly challenging in this area, due to the inherent lack of Figure 1. β-diketiminate Mg complexes employed in this study
stability of lithiated fluoroarenes, which even at cryogenic
Opening wider the synthetic relevance of β-diketiminate
stabilised magnesium complexes, here we present their
applications for functionalisation of challenging fluoroaromatic
substrates, uncovering their ability to promote regioselective
metallation and C-F bond activation processes.
conditions can eliminate LiF, to form benzyne intermediates as
well as engaging in complex cascade processes involving
8
autometallation steps. In contrast, while organomagnesium
bases have barely been considered for deprotonation of
b
3
fluoroarenes, probably as a consequence of their reduced
metallating power, recent reports have shown that Grignard
We started our investigations assessing the reactivity of
1 with
a range of fluorinated aromatics at room temperature in d8-
THF in a J. Young NMR tube (Table 1). All reactions were
1 19
followed by H and F NMR spectroscopy (see SI for details).
WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde,
Glasgow, G1 1XL (UK); e-mail: eva.hevia@strath.ac.uk
Electronic Supplementary Information (ESI) available: [Experimental, spectroscopic
and crystallographic details]. See DOI: 10.1039/x0xx00000x
While
1
fails to deprotonate fluorobenzene (entry 1), even
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under forcing conditions (80 C, 24h), the reaction with 1,3-
Journal Name
o
1
[a] Yields determined by H NMR using ferrocene as internal standard after
1h at RT. [b] Isolated yields in parenthesis after 2h at RT. [c] No reaction
after 24h, heating at 80 °C. [d] Full conversion after 2h at RT. [e] General
Dipp
difluorobenzene afforded [2-( Nacnac)Mg-1,3-F
2
-C
3a) in 74% yield after just one hour at room temperature
entry 2). Further monitoring of this reaction showed that after
6 2 3
F H ]
(
(
conditions: 5 mol% Pd(PPh
Pd(PPh and 2 equivalents PhI, and [g] 2 equivalents PhI. [h] Reacted as
an isolated solid. [i] Prepared in situ and reacted.
3
)4, 1.25 equivalents PhI. Except [f] 10 mol%
3 4
)
2h the conversion of
1 into 3a is nearly quantitative. Similarly,
1,3,5-trifluorobenzene (2 hours), 1,2,4,5-tetrafluorobenzene Insight into the solution constitutions of these compounds in
and pentafluorobenzene (both 1 hour) all undergo facile Mg-H THF was gained by Diffusion Ordered Spectroscopy (DOSY)
1
2
exchange processes quantitatively at room temperature giving experiments, which suggest these new complexes adopt
Dipp
Dipp
[
2-( Nacnac)Mg-1,3,5-F
3
-C
6
F
3
Dipp
H
2
]
(
3b), [3-( Nacnac)Mg- monomeric structures in this coordinating solvent. Consistent
H] (3c) and [( Nacnac)Mg-C ] (3d) (entries with this solution picture, X-ray crystallographic studies
, 4 and 5). This reactivity pattern is consistent with the revealed the monomeric structure of 3c
confirming
1
,2,4,5,-F
4
-C
6
F
4
6 5
F
3
,
increase in the C-H acidity of fluoroarenes as the number of F magnesiation of 1,2,4,5-tetrafluorobenzene had occurred
1
1
Dipp
atoms in the aromatic ring increases. . Metallation products (Figure 2) with a {( Nacnac)Mg} fragment occupying the
a-3d were isolated as pure crystalline solids in yields ranging position previously filled by a H atom, binding at the C3 atom
from 43-66% (see SI for experimental details and full of the fluoroarene [i.e., C30 in Fig 1, Mg1-C30, 2.1705(19) Å].
3
spectroscopic characterization).
Although the Mg-F distances are too long to suggest some
significant interaction, F4 forms a shorter contact than F1
[3.2773 vs 3.3214 Å]. While from a synthetic viewpoint the
isolation and characterization of 3a-d as the result of a direct
Mg-H exchange process is unique, it should be noted that the
structure of 3c is similar to those reported by Crimmin for the
products of C-F bond addition of perfluorinated arenes to Mg-
Table 1 Metallation of fluorinated aromatics with 1, and subsequent Negishi
cross-coupling with iodobenzene where applicable.
F
F
(
i) ZnCl
(ii) PhI, Pd(PPh
F
2
1
(1 eq)
M
3
)
Ph
4
d
8
THF, 1h, rt
o
THF, 18h,80 C
F
3a-e
F
F
4
a-e
Dipp
7b
= {(DippNacnac)Mg (THF)}
2
Mg bonds of Mg(I) complex [{( Nacnac)Mg} ].
M
Metallated Product
Crossꢀcoupling Product
Substrate
[a,b]
[e]
Yield %
Yield %
fluorobenzene
ꢀ
[
c]
0
1
,3ꢀdifluorobenzene
[
d]
[f,h]
Figure 2. Molecular structure of 3c. Hydrogen atoms are omitted for clarity and
(
3a) 74 (66)
(4a) (64)
thermal ellipsoids are rendered at 30% probability.
These findings establish
base for the metallation of hypersensitive fluorinated organic
building blocks. A significant advantage of over conventional
1 as an effective and regioselective
1
,3,5ꢀtrifluorobenzene
[
d]
[g,i]
(
3b) 78 (43)
(4b) (63)
1
s-block metallating reagents is its ability to trap and stabilise
the emergent fluoroaryl anions. Metallated intermediates 3a-e
display a remarkable stability in solution. Taking 3b as an
1
,2,4,5ꢀ
tetrafluorobenzene
1
19
exemplar, H and F NMR reaction monitoring experiments in
the presence of benzyne trapping agents such as durene or
[
i]
(3c) ≥99 (66)
(4c) (65)
1,3-diphenylisobenzofuran
show
no
evidence
of
decomposition, even in the face of harsh reaction conditions
o
80 C, 5h). Considering the relative polarity of the Mg-C bonds
(
pentafluorobenzene
and the proximity of F atoms to Mg (vide supra), the
robustness of these complexes may seem rather unexpected.
However, this can be rationalised in terms of the steric
protection provided by the bulky β-diketiminate ligand,
providing shelter to the newly formed Mg-C bond, which
confers a greater degree of stability to these sensitive
carbanionic species. This behaviour contrasts with our recent
work on the alumination of fluoroarenes by using Li/Al basic
combinations, where the metallated products decompose at
room temperature to eliminate lithium fluoride aluminate
[
i]
(
3d) ≥99 (56)
(4d) (68)
2
ꢀ(2,4ꢀ
difluorophenyl)pyridine
[
i]
(
3e) ≥99 (68)
(4e) (69)
2
| J. Name., 2012, 00, 1-3
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1
].
3
[LiAl(F)(TMP)iBu
2
Chen recently reported
a similarly 7a can be envisaged as a cross-coupling product between 2
negative result
for a novel scandium-mediated and ppf via cleavage of the C-F bond ortho to the pyridyl ring,
dehydrofluorination of fluoroarenes, proposed to occur by without the need of transition metal catalysis. A proposed
initial metallation of the substrate which in turn undergoes rationale for the formation of 7a is depicted in Scheme 1.
rapid fluoride elimination with subsequent benzyne Firstly, the substrate can coordinate to
2
via a dative bond
in Scheme 1). While this
Exemplifying the further functionalisation of these sterically complex cannot be intercepted, related coordination adducts
shielded magnesiated carbanions, complexes 3a-d as well as of have been structurally defined for pyrazine and N-methyl
complex 3e (resulting from the metallation of ppf in the imidazole. This scenario can be considered to doubly activate
1
4
formation.
from the pyridyl nitrogen atom (I
2
1
0
1
0a
position the C3 atom of the fluoroaryl ring), proved to be the ortho C-F bond by both the pyridyl directing group (which
valuable precursors in Negishi type cross-coupling reactions, is also electron-withdrawing) and the proximity of the fluorine
using iodobenzene as the electrophilic coupling partner (Table to the metal atom. This step seems to be key as other
1). Reactions were carried out using stoichiometric amounts of fluoroarenes where pre-coordination is not possible such as
ZnCl , two equivalents of PhI and 10 mol % of Pd(PPh ) (see SI C F or C HF fail to react with 2. Secondly, ppf is now
5
2
3 4
6
6
6
for details). After an organic work-up, and flash column predisposed for the addition of the alkyl group to the benzene
chromatography the relevant non-symmetric bis(aryls) 4a-e ring forming a new C-C bond (II in Scheme 1), followed by
were obtained in isolated yields ranging from 63-69% (Table 1 elimination of fluoride complex
and SI). bond, affording alkylation product 7a. A related pyridinyl
Illustrating the kinetic attenuation of the metallating power of coordination assisted ortho-selective C-F bond activation
5, via the cleavage of the C-F
Dipp
n
butyl base [( Nacnac)Mg( Bu)THF] (
2), when treated with process has been reported by Zhang for Pd-catalysed hydro-
1
,3,5-trifluorobenzene no reaction was observed at room defluorination of polyfluoroarenes with Et SiH. Within Mg
7
1
3
temperature and formation of metallation product 3b only chemistry, Cao has noted a similar coordination effect for the
occurs at elevated temperatures (60 °C for 138 hours). reactions of Grignard reagents with polyfluoroarenes, although
Notably, reactions between
resulted, in some cases, in formation of small amounts of are provided and conditions required are significantly harsher
highly insoluble crystals discovered to be than those observed for 7a (2.5 molar excess of RMgX, 6-24h
NacnacMgF(THF)} ] (
2 and the present fluorobenzenes no insights on the constitution of the metallated intermediates
Dipp
15,16
o
9d
[{
5).
at 65 C). Interestingly our approach is not limited to 2 and it
2
Dipp
As discussed above, since 3a-e are remarkably stable towards also works well for aryl complex [ NacnacMg(C H )THF] (13
6
)
5
fluoride elimination even at high temperatures, this suggested affording C-F arylation product 7b in an 82% yield (Scheme 1).
an alternative reaction pathway for with these fluoroarene The possibility that formation of 7a-b occurring via an
substrates involving activation of their C-F bonds. Interestingly, alternative radical pathway was investigated by carrying out
reaction of with ppf over 24 hours at room temperature in the reaction of and ppf in the presence of radical trapping
2
2
2
toluene resulted in almost quantitative formation of fluoride agent TEMPO (2,2,6,6-tetramethyl-1-piperodomyloxy). In
complex 5, indicating that C-F bond activation of the substrate these studies TEMPO, which is known to exhibit extensive
1
8
has readily occurred. Investigating this reactivity more coordination chemistry with Mg, acts as a mere spectator,
thoroughly, the reaction filtrate was subjected to aqueous affording 7a in comparable yields to those observed when
work-up and revealed that a new compound, 2-(2-butyl-4- TEMPO is not present (vide supra).
Ar*
Ar*
Ar*
fluorophenyl)pyridine), 7a, formed in 92% yield (Scheme 1).
N
N
N
Bu
N
N
Bu
F
Mg TMP
+
Mg
+
Mg
TMP(H)
F
N
N
THF
THF
Ar*
Ar*
N
Ar*
Ar*
2
1
Ar* 2
ppf
N
N
THF
R
N
R
F
Mg
F
Mg
d ꢀTHF,
coordination
d8ꢀTHF,
RT, 5 h
8
F
N
F
o
I
80 C, 24 h
N
Ar*
N
Ar*
2
6
(R=Bu)
(R= Ph)
C-C bond
formation
F
F
N
Ar*
THF
Ar*
Ar*
Ar*
Mg
Bu
Ar*
N THF
Ar*
N
Ar*
F
N
Bu
N
F
N
fluoride
elimination
N
N
+
Mg
Mg
Mg
+
N
N
N
N
F
F
THF
5
F
F
F
N
THF
N
N
Ar*
Mg
Mg
Mg
O
3e
Ar*
Ar*
F
N
N
THF
Ar*
7a
Ar*
Ar*
Ar*
2
II
R
F
5
C-H activation
Scheme 2 Tuning C-H and C-F activiation of ppf with magnesium complexes
and
C-F activation
R
1
N
2
F
7
7
a (R= Bu) 92%
b (R = Ph) 82%
Considering the divergent reactivities of
1 and 2 towards ppf,
Scheme 1 Proposed mechanism for magnesium-mediated C-F alkylation and arylation which enable the regioselective activation of a C-H or C-F bond
of ppf by monomeric magnesium complexes 2 and 3.
of this substrate, to afford 3e or 7a respectively, a competition
experiment was performed between stoichiometric and
1, 2
1 19
ppf in a 1:1:1 ratio (Scheme 2, left). H and F NMR
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monitoring of the reaction revealed that under these
Notes and references
conditions C-H metallation product 3e is regioselectively
1
a) J. Wang, M. Sánchez-Roselló, J. Aceña, C. Del Pozo, A. E.
Sorochinsky, S. Fustero, V. A. Soloshonok, H. Liu, Chem. Rev.
2014, 114, 2432; b) S. Purser, P. R. Moore, S. Swallow, V.
Gouverneur, Chem. Soc. Rev. 2008, 37, 320.
obtained, whereas Bu complex
demonstrates the kinetic superiority of
is reacted with one equivalent of the amine TMP(H) and ppf at
2
remains intact. This
1. Contrastingly when
2
o
2
3
X.-H. Xu, G.-M. Yao, Y-M. Li, J.-H. Lu, C.-J Lin, X. Wang, C.-H.
Kong, J. Nat. Prod. 2003, 66, 285.
a) P. L. Coe, A. J. Waring, T. D. Yarwood, J. Chem. Soc. Perkin
Trans. 1995, 2729; b) R. J. Harper. Jr, E. J. Soloski, C.
Tamborski, J. Org. Chem. 1964, 29, 2385; c) L. Gupta, A. C.
8
0 C, only formation of C-F activation product 7a and fluoride
complex 5 is observed (Scheme 2, right). This is somehow
surprising as under these more forcing conditions it could have
been anticipated that some of the amine TMP(H) could react
with
ppf to form metallation product 3e. Even if
allowed to stir for 3 h before introducing ppf, only formation
2
to afford amide
1
in situ, which reacts faster than
2
with
Hoepker, K. J. Singh, D. B. Collum, J. Org. Chem. 2009, 74
231.
M. F. Kuehnel, D. Lentz, T. Braun, Angew. Chem. Int. Ed.
013, 52, 3328
a) D. O’Hagan, Chem. Soc. Rev. 2008, 37, 308; b) E. Clot, O.
Eisenstein, N. Jasim, S. A. Macgregor, J. E. McGrady, R. N.
Perutz, Acc. Chem. Res. 2011, 44, 333.
M. K. Cybulski, D. McKay, S. A. Macgregor, M. F. Mahon, M.
K. Whittlesey, Angew. Chem. Int. Ed. 2017, 56, 1515.
a) M. R. Crimmin, M. J. Butler, A. J. P. White, Chem. Commun.
,
2
1
and TMP(H) are
4
5
2
1
9
of 5 and 7a is observed.
These studies illustrate how the chemical profiles of these
Mg(II) β-diketiminate complexes can be finely tuned for C-H/C-
F activation by modifying the nature of the remaining ligand
6
7
(
Bu vs TMP). This can be exploited for tandem
functionalization of organic molecules as shown in Scheme 3
for benzofuran. Reaction with accomplishes direct
magnesiation of its α-C-H bond, affording (78% isolated
yield) which structure was established by X-ray crystallography
Scheme 3, see SI for details). Addition of ppf enables the
activation of the ortho C-F bond, to give coupled product 7c
71% yield) resulting from the cross coupling of benzofuran
and ppf, with the concomitant elimination of fluoride complex
2
015, 51, 15994; b) C. Bakewell, A. J. P. White, M. Crimmin, J.
1
Am. Chem. Soc. 2016, 138, 12763; c) T. Chu, Y. Boyko, I.
Korobkov, G. I. Nikonov, Organometallics 2015, 34, 5363. (d)
V. S. V. S. N. Swamy, N. Parvin, K. V. Raj, K. Vanka, S. S.
Sen, Chem. Commun. 2017, 53, 9850; (e) A. Jana, P. P.
Samuel, G. Tavčar, H. W. Roesky, C. Schulzke, J. Am. Chem.
Soc. 2010, 132, 10164.
8
(
(
8
9
a) J. Clayden in Organolithiums: Selectivity for Synthesis,
Elsevier, Oxford, 2002; b) V. Snieckus, Chem. Rev. 1990, 90,
79; c) F. Mongin, M. Schlosser, Tet. Lett, 1996, 37, 6551; d)
8
5.
Ar*
Ar*
M. Schlosser, Angew. Chem. Int. Ed. 2005, 44, 376; e) R.
Chinchilla, C. Nájera, M. Yus, Chem. Rev, 2004, 104, 2667.
a) F. Lu, H. Sun, A. Du, L. Feng, X. Li, Org. Lett. 2014, 16, 772–
775; b) K. Matsubara, T. Ishibashi, Y. Koga, Org. Lett. 2009,
N
N
H
O
N
N
5h, RT, THF
ꢀ TMP(H)
THF
O
Mg TMP
+
Mg
Ar*
Ar*
8
C-H activation
11, 1765; c) T. Hatakeyama, S. Ito, M. Nakamura, E.
3
days, RT,
THF
F
Nakamura, J. Am. Chem. Soc. 2005, 127, 14192; d) Y. Xiong, J.
Wu, S. Xiao, J. Xiao, S. Cao, J. Org. Chem. 2013, 78, 4599.
10 a) L. Davin, R. McLellan, A. Hernán-Gómez, W. Clegg, A. R.
N
C-F activation
ppf
5
F
Kennedy, M. Mertens, I. A. Stepek, E. Hevia, Chem. Commun.
2
017, 53, 3653; b) S. E. Baillie, V. L. Blair, T. D. Bradley, W.
Clegg, J. Cowan, R. W. Harrington, A. Hernán-Gómez, A. R.
Kennedy, Z. Livingstone, E. Hevia, Chem. Sci. 2013, , 1895.
N
4
+
1
1 H. H. Büker, N. M. M. Nibbering, D. Espinosa, F. Mongin, M.
Schlosser, Tet. Lett. 1997, 38, 8519.
O
7c
F
1
1
2 R. Neufeld, D. Stalke, Chem. Sci. 2015, 6, 3354.
3 R. McLellan, M. Uzelac, A. R. Kennedy, E. Hevia, R. E. Mulvey,
Angew. Chem. Int. Ed. 2017, 56, 9566.
Scheme 3. One pot coupling of benzofuran and ppf via tandem Mg-mediated C-
H/C-F bond activation processes.
1
1
4 Chu, X. Han, C. E. Kefalidis, J. Zhou, L. Maron, X. Leng, Y.
Chen, J. Am. Chem. Soc. 2014, 136, 10894.
In conclusion, two new Mg-mediated strategies for the
functionalization of challenging fluoroarenes via C-H or C-F
bond activation processes are presented. Exploiting ligand-
ligand cooperation, through a β-diketiminato-sheltered Mg
centers, the reactivity of these systems can be finely tuned
allowing excellent control of the regio- and chemoselectivity
under mild reaction conditions. Tandem protocols, combining
these two new reactivity profiles in sequence have uncovered
5 H. Hao, H. W. Roesky, Y. Ding, C. Cui, M. Schormann, H.-G.
Schmidt, M. Noltemeyer, B. Žemva, J. Fluor. Chem. 2002,
115, 143.
Dipp
1
1
2
6 Fluoride complex [{ NacnacMgF(THF)} ] (5) has also been
identified as a byproduct for reaction of perfluoroarenes
Dipp
2
with Mg(I) complex [{( Nacnac)Mg} ], see reference 7b.
7 Z. Chen, C. Y. He, Z. Yin. C. Yi, Z. Zhang, Angew. Chem. Int. Ed.
2013, 52, 5813.
a new method for transition metal-free cross couplings of 18 G. C. Forbes, A. R. Kennedy, R. E. Mulvey, P. J. A. Rodger,
Chem Commun. 2001, 1400.
heterocycles with ppf
.
1
9 The lack of reactivity of
reported by Gibson for the reactions of
NH(SiMe which form the relevant Mg amide complexes,
see: A. P. Dove, V. C. Gibson, P. Hormirun, E. L. Marshall, J. A.
Segal, A. J. P. White, D. J. Williams, Dalton Trans. 2003, 3088.
2 with TMP(H) contrasts with that
i
2
2
with NH Pr or
3 2
)
We thank the European Research Council (ERC StG, MixMetApps)
and the EPSRC (EP/N011384/1) for their generous sponsorship of
this research. Data supporting this research are openly available
from www.datasettbc.com
4
| J. Name., 2012, 00, 1-3
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DOI: 10.1039/C7CC07193K
Ar*
F
(i)
N
N
Mg TMP Ph
N
F
Ar*
H
F
F
N
(
ii) PhI, Pd cat
C-H bond activation
Ar*
N
Mg
Bu
THF
Bu
H
N
N
Ar*
F
C-F bond activation
Text for TOC
Using β-diketiminate sheltered Mg manifolds with an alkyl or amido ligand
enables fine-tuning of their reactivity for chemoselective functionalization of
fluoroarenes via either Mg-H or Mg-F exchange.