Pd-Catalyzed Suzuki-Miyaura and Hiyama-Denmark Couplings of Aryl Sulfamates

Article abstract of DOI:10.1021/acs.orglett.6b02330

Using a recently discovered precatalyst, the first Pd-catalyzed Suzuki-Miyaura reactions using aryl sulfamates that occur at room temperature are reported. In complementary work, it is demonstrated that a related precatalyst can facilitate the coupling of aryl silanolates, which are less toxic and reactive nucleophiles than boronic acids with aryl chlorides. By combining our results using modern electrophiles and nucleophiles, the first Hiyama-Denmark reactions using aryl sulfamates are reported.

Full text of DOI:10.1021/acs.orglett.6b02330

Letter
pubs.acs.org/OrgLett
Pd-Catalyzed Suzuki−Miyaura and Hiyama−Denmark Couplings of
Aryl Sulfamates
Patrick R. Melvin,† Nilay Hazari,*,† Megan Mohadjer Beromi,† Hemali P. Shah,† and Michael J. Williams‡
†Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520, United States
‡Department of Process Chemistry, Merck Research Laboratories, Rahway, New Jersey 07065, United States
S
* Supporting Information
ABSTRACT: Using a recently discovered precatalyst, the first Pd-catalyzed Suzuki−Miyaura reactions using aryl sulfamates that
occur at room temperature are reported. In complementary work, it is demonstrated that a related precatalyst can facilitate the
coupling of aryl silanolates, which are less toxic and reactive nucleophiles than boronic acids with aryl chlorides. By combining
our results using modern electrophiles and nucleophiles, the first Hiyama−Denmark reactions using aryl sulfamates are reported.
shown similar toxicity problems, yet their application in cross-
he discovery of Pd-catalyzed cross-coupling reactions has
Tresulted in major advances in the synthesis of both coupling is limited.13 Early Hiyama couplings required fluoride-
pharmaceuticals and fine chemicals.1 Typically, aryl halides are
containing additives to promote transmetalation, which limited
the utility of the reactions.14 Subsequently, Denmark demon-
strated that when aryl silanols and their derivatives are used as
nucleophiles, only a Brønsted base is required for activation,
eliminating the need for fluoride additives.15 Currently, this
chemistry remains most effective with aryl bromides and
iodides,16 and the scope of these reactions needs to be broadened
to make the Hiyama−Denmark reaction a true alternative to
Suzuki−Miyaura couplings.
used as the electrophile in these reactions.1 However, phenolic
derivatives offer their own unique advantages.2 They not only are
robust and trivial to prepare from ubiquitous phenols3 but can
provide routes to prefunctionalize the electrophile through C−H
activation and directed ortho-metalation.4 Although simple
phenol derivatives such as aryl sulfonates have been used for
many years in cross-coupling reactions,2b,5 these moieties are not
useful directing groups for C−H activation. Therefore, there is
interest in the use of aryl sulfamates as electrophiles in cross-
coupling reactions.2b−d The first reports of Suzuki−Miyaura
reactions involving aryl sulfamates utilized Ni catalysts but
required elevated temperatures (>100 °C) and catalyst loadings
(5−10 mol %).6 Despite further studies on Ni-catalyzed Suzuki−
Miyaura reactions with aryl sulfamates,7 there is still only one
system that can facilitate the coupling of a small number of
naphthyl sulfamates with boronic acids at room temperature.8 In
related chemistry, Percec and co-workers reported Ni systems for
the room temperature coupling of aryl sulfamates with
neopentylglycol boronates using catalyst loadings of 5−10 mol
%.9 While these results are impressive, neopentylglycol
boronates are not commercially available and are less atom
efficient than boronic acids. In the last 3 years, there have been
reports of Pd catalysts for Suzuki−Miyaura reactions with aryl
sulfamates, but these systems also require elevated temperatures
(80−100 °C) and catalyst loadings (4−10 mol %).10 These
conditions can limit the utility and functional group tolerance of
Suzuki−Miyaura reactions between boronic acids and aryl
sulfamates.
Recently, we described new precatalysts for cross-coupling,
(η3-1-tBu-indenyl)Pd(L)(Cl), which are compatible with both
phosphine and NHC ligands and are commercially available.17
The precatalysts can be generated in situ through the reaction of
the unligated dimeric precursor (η3-1-tBu-indenyl)2Pd2(μ-Cl)2
(1) with 2 equiv of free ligand, which is convenient for ligand
screening. We demonstrated that our precatalysts are highly
active for a range of standard cross-coupling reactions using aryl
halides as electrophiles, including Buchwald−Hartwig and α-
arylation reactions and Suzuki−Miyaura couplings using both
aryl and alkyl organoboranes.17 Here, we demonstrate the ability
of our precatalysts to broaden the scope of cross-coupling
(Figure 1). Through application of ligand screening, we describe
the first examples of Pd-catalyzed Suzuki−Miyaura reactions
using aryl sulfamates at room temperature. Additionally, our
precatalysts are compatible with less reactive nucleophiles and
are capable of coupling aryl silanolates with a variety of aryl
chlorides. The culmination of this work is the coupling of aryl
silanolates with aryl sulfamates, which represent the first
Hiyama−Denmark reactions using aryl sulfamates.
Based on pioneering work by Garg and co-workers, Ni
precatalysts have been preferred for Suzuki−Miyaura reactions
Organoboranes, utilized in Suzuki−Miyaura reactions, are the
most common nucleophiles in cross-coupling.11 This is in part
due to the perceived low toxicity of boronic acids. However,
recent reports suggest that some, but not all, boronic acids are
mutagenic.12 In contrast, silicon-based nucleophiles have not
Received: August 5, 2016
© XXXX American Chemical Society
A
DOI: 10.1021/acs.orglett.6b02330
Org. Lett. XXXX, XXX, XXX−XXX

Organic Letters
Letter
addition of methanol improves the efficiency of this reaction: (i)
both the boronic acid and the base are more soluble, and (ii)
methanol can potentially play a key role in the activation of the
precatalyst from Pd(II) to Pd(0).19 Finally, switching the base
from K3PO4 to K2CO3 provided full conversion to product at
room temperature (entry 7).
Using our optimized ligand and conditions, we expanded the
substrate scope to other boronic acids and aryl sulfamates
(Figure 2). In these reactions, we used the ligated XPhos
Figure 1. Summary of this work: (a) first examples of room-temperature
Pd-catalyzed Suzuki−Miyaura couplings using aryl sulfamates; (b)
Hiyama−Denmark couplings using aryl chlorides; and (c) Hiyama−
Denmark couplings with aryl sulfamates.
using aryl sulfamates.6 This is because it is proposed that
oxidative addition of the aryl sulfamate is more facile for Ni
compared to Pd.6b However, there have only been limited
computational studies of oxidative addition of aryl sulfamates to
Pd,6b and the effects of state-of-the-art ligands for cross-coupling,
which can promote oxidative addition, are unclear.18 We
performed a ligand screen for the coupling of 1-naphthyl
sulfamate with (4-methoxyphenyl)boronic acid using our
unligated dimeric precursor 1 and 2 equiv of a range of free
ligands (Table 1 and SI). Using K3PO4 as the base and toluene as
Table 1. Yields for Ligand Screening for Pd-Catalyzed
Suzuki−Miyaura Reactions of Aryl Sulfamates
Figure 2. Isolated yields of products in Suzuki−Miyaura reactions using
naphthyl and phenyl sulfamates. Conditions: sulfamate (0.1 mmol),
boronic acid (0.15 mmol), K2CO3 (0.2 mmol), Pd-XPhos precatalyst
a
a
(0.0025 mmol), toluene (0.66 mL), methanol (0.33 mL). Performed
on 1 mmol scale in relation to aryl sulfamate. bPerformed at 80 °C for 24
hours. Yields are the average of two runs.
b
entry
ligand
PtBu3
solvent
toluene
base
yield (%)
precatalyst (Pd-XPhos) instead of the in situ generated system
for operational simplicity and to ensure the ideal 1:1 Pd/ligand
ratio. Couplings using naphthyl (Figure 2) and substituted
naphthyl sulfamates (see SI) were successful with a variety of
boronic acids at room temperature. Even 2-heteroaryl boronic
acids, which readily undergo protodeborylation,20 yielded
product in greater than 95% yield (2d−f). In general, oxidative
addition of naphthyl sulfamates is easier than phenyl
sulfamates,2g,21 but our optimized system facilitated the coupling
of 4-(trifluoromethyl)phenyl sulfamate with both an unactivated
boronic acid as well as a 2-heteroaryl boronic acid at room
temperature (Figure 2). Unsubstituted phenyl sulfamate proved
to be more difficult and excellent yields were only obtained when
the reactions were performed at 80 °C.
These results represent the first examples of Pd-catalyzed
Suzuki−Miyaura reactions involving aryl sulfamates at room
temperature. Furthermore, the conditions employed require a
significantly lower number of equivalents of boronic acid (1.5
equiv vs 2.5 equiv) as well as external base (2.5 equiv vs 4.5 equiv)
compared to state-of-art Ni catalysts.6 Our results suggest that it
may be possible to develop systems for the coupling of even less
activated phenol derived electrophiles such as aryl carbamates
and esters, which have been proposed to be incompatible with Pd
catalysts.2g
1
2
3
4
K3PO4
K3PO4
K3PO4
K3PO4
K3PO4
K3PO4
K2CO3
<5
42
48
61
97
84
98
SPhos
RuPhos
XPhos
XPhos
XPhos
XPhos
toluene
toluene
toluene
c
5
toluene
d
6
toluene/MeOH
toluene/MeOH
d
7
a
Conditions: 1-naphthyl sulfamate (0.1 mmol), (4-methoxyphenyl)-
boronic acid (0.15 mmol), base (0.2 mmol), 1 (0.00125 mmol), ligand
(0.0025 mmol), toluene (1 mL), 25 °C, 4 h. Yields are the average of
two runs and were determined by GC. Performed at 50 °C. Solvent:
toluene (0.66 mL), methanol (0.33 mL).
b
c
d
the solvent, no product was observed using simple phosphines
such as PCy3, PtBu3, or PPh3 or the N-heterocycle carbene ligand
IPr (see SI), consistent with computational predictions from
Garg and co-workers.6b When Buchwald-type phosphines that
are designed to increase the rate of oxidative addition18 were used
as the ancillary ligand, moderate conversions were achieved at
room temperature (entries 2−4). Consistent with our previous
results,17 our precatalyst gives superior results compared to other
related systems, such as Nolan’s (η3-allyl)Pd(L)(Cl) precatalysts
(see SI).1a Using XPhos, complete conversion was achieved at 50
°C (entry 5). When methanol was used as a co-solvent, excellent
conversion was obtained using XPhos at room temperature
(entry 6). We suggest that there are two main reasons why the
The reactions with aryl sulfamates show that our precatalysts
are compatible with valuable electrophiles. We were also
interested in exploring their activity with modern nucleophiles
B
DOI: 10.1021/acs.orglett.6b02330
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Organic Letters
Letter
such as organosilanes. Denmark and co-workers have advanced
the field of fluoride-free Hiyama coupling through their discovery
of silanolates as viable nucleophiles.15 For example, using
Pd(PtBu3)2, they were able to effectively couple heteroaryl
iodides and bromides with various aryl and alkenyl silanolates.16a
However, examples of the coupling of less reactive aryl chlorides
with aryl silanolates are rare and generally require catalyst
loadings of 5 mol % or more and temperatures ranging from 70 to
100 °C.16 Given the ubiquitous nature of aryl chlorides,
developing systems that can perform Hiyama−Denmark
reactions using these electrophiles at milder conditions would
be beneficial.22
Using conditions similar to those reported by Denmark for
coupling aryl iodides and bromides,16a a ligand screen was
performed using 1, free ligand, 4-(trifluoromethyl)phenyl
chloride, and 4-(methoxy)phenyl silanolate, which was prepared
using a literature method.16a In an analogous fashion to
Denmark’s results,16a the best activity was observed using
PtBu3 as the ancillary ligand. Many other standard cross-coupling
ligands (PPh3, PCy3, IPr) were unsuccessful at coupling the
silanolate with the aryl chloride (see SI). Notably, several
Buchwald-type phosphines were moderately effective in this
transformation (SPhos and XPhos).
To further show the versatility of our precatalyst system, we
aimed to couple silanolates with sulfamates, a combination of
substrates that has never been used together. Initial efforts to
combine 1-naphthyl sulfamate with aryl silanolates proved to be
unsuccessful using the conditions described in Figure 3. This is
presumably related to the fact that our precatalyst ligated with
PtBu3 was inactive for Suzuki−Miyaura reactions with aryl
sulfamates. However, using XPhos as the ligand, some activity
was observed for the coupling of 2-naphthyl sulfamate with 4-
methoxyphenyl silanolate (Table 2, entry 1). Changing the
Table 2. Yields for Ligand Screening for Pd-Catalyzed
a
Coupling of Aryl Silanolates with Aryl Sulfamates
b
temp
(°C)
yield
(%)
entry
ligand
Pd loading (mol %)
additive
1
2
3
4
5
6
XPhos
2.5
2.5
5.0
5.0
5.0
5.0
5.0
none
110
110
110
110
110
110
80
18
37
62
<5
<5
95
98
RuPhos
RuPhos
RuPhos
RuPhos
RuPhos
RuPhos
none
none
NaOMe
NaOtBu
c
With optimal conditions and ligand found, our focus shifted to
expanding the scope to other aryl chlorides (Figure 3). Using the
RuPhos
RuPhos
d
c
7
a
Conditions: 4−(methoxy)phenyl silanolate (0.2 mmol), 2-naphthyl
b
sulfamate (0.1 mmol), toluene (1 mL), 8 h. Yields are the average of
two runs and were determined by GC. 5.0 mol % of RuPhos. 24 h.
c
d
ligand to RuPhos resulted in increased yields, consistent with the
trend seen for Hiyama−Denmark coupling with aryl chlorides
(see SI). To further improve the yield, we screened potentially
useful additives. Addition of external bases did not lead to
coupling, as they caused degradation of the aryl sulfamate
(entries 4 and 5). When 5.0 mol % of free RuPhos was added, the
yield of product increased (entry 6), as has been observed in
some Buchwald−Hartwig reactions.17 It is unclear why the
addition of excess RuPhos assists in the reaction, but it could
reduce catalyst decomposition through the formation of
unligated Pd(0) species. For our best conditions, the temper-
ature could be lowered to 80 °C while still achieving high yields,
albeit with longer reaction times (entry 7).
Figure 3. Isolated yields of products for silanolate couplings with aryl
chlorides. Conditions: silanolate (0.2 mmol), aryl chloride (0.1 mmol),
Pd-PtBu3 precatalyst (0.0025 mmol), toluene (1 mL), 70 °C, 4 hours.
aPerformed on 1 mmol scale in relation to aryl chloride. bPerformed at
90 °C. Yields are the average of two runs.
This method is compatible with a variety of 2-naphthyl
sulfamate derivatives (Figure 4). Using both 4-(methoxy)phenyl
and naphthyl silanolates, heterocyclic sulfamates as well as
sulfamates with ester and ether functionalities could be coupled
with good to excellent isolated yields (4b−d). When moving to
phenyl sulfamates, it was necessary to increase the equivalents of
silanolate. For phenyl sulfamates with electron-withdrawing
groups, good to excellent yields were obtained (4i−k), whereas
for unsubstituted and 4-fluorophenyl sulfamate there was a
decrease in yield (4h,l). No product was observed with 1-
naphthyl sulfamate derivatives, presumably due to the increased
steric bulk of these substrates. Our results represent the first use
of phenol-derived electrophiles, which can be used as directing
groups, in Hiyama−Denmark reactions.
electron-rich 4-(methoxy)phenyl silanolate,16a seven aryl
chlorides were coupled using the Pd−PtBu3 precatalyst. In
each case, isolated yields were greater than 85%, including
deactivated substrates (3b and 3f) as well as heterocyclic aryl
chlorides (3c−e,g). The scope of these reactions with 1-naphthyl
(3h−o) and 4-(trifluoromethyl)phenyl (3p−v) silanolates16a is
shown in Figure 3. Again, yields greater than 85% were achieved
using the same conditions. No significant differences exist
between the silanolate substrates, despite the differences in their
electronic properties. In total, we have performed over 20
different Hiyama−Denmark reactions using aryl chlorides. Our
results continue the expansion of this exciting cross-coupling
reaction and highlight the improved activity observed with our
precatalyst.
In conclusion, we have demonstrated the utility of our (1-tBu-
indenyl)Pd(L)(Cl) precatalysts by describing the room-temper-
ature Pd-catalyzed Suzuki−Miyaura couplings of aryl sulfamates,
Hiyama−Denmark reactions with aryl chlorides, and the first
examples of Hiyama−Denmark couplings using aryl sulfamates.
C
DOI: 10.1021/acs.orglett.6b02330
Org. Lett. XXXX, XXX, XXX−XXX

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Letter
(c) Knappke, C. E. I.; Jacobi von Wangelin, A. Angew. Chem., Int. Ed.
2010, 49, 3568. (d) Board, J.; Cosman, J. L.; Rantanen, T.; Singh, S. P.;
Snieckus, V. Platinum Met. Rev. 2013, 57, 234.
(5) (a) Norberg, A. M.; Sanchez, L.; Maleczka, R. E., Jr. Curr. Opin.
Drug Discovery Dev. 2008, 11, 853. (b) So, C. M.; Kwong, F. Y. Chem.
Soc. Rev. 2011, 40, 4963.
(6) (a) Quasdorf, K. W.; Riener, M.; Petrova, K. V.; Garg, N. K. J. Am.
Chem. Soc. 2009, 131, 17748. (b) Quasdorf, K. W.; Antoft-Finch, A.; Liu,
P.; Silberstein, A. L.; Komaromi, A.; Blackburn, T.; Ramgren, S. D.;
Houk, K. N.; Snieckus, V.; Garg, N. K. J. Am. Chem. Soc. 2011, 133, 6352.
(7) (a) Chen, G. J.; Han, F. S. Eur. J. Org. Chem. 2012, 2012, 3575.
(b) Ramgren, S. D.; Hie, L.; Ye, Y.; Garg, N. K. Org. Lett. 2013, 15, 3950.
(c) Ke, H.; Chen, X.; Zou, G. J. Org. Chem. 2014, 79, 7132.
(8) Beromi, M. M.; Nova, A.; Balcells, D.; Brasacchio, A. M.; Brudvig,
G. W.; Guard, L. M.; Hazari, N.; Vinyard, D. J. J. Am. Chem. Soc. 2016,
submitted.
(9) (a) Leowanawat, P.; Zhang, N.; Resmerita, A. M.; Rosen, B. M.;
Percec, V. J. Org. Chem. 2011, 76, 9946. (b) Leowanawat, P.; Zhang, N.;
Safi, M.; Hoffman, D. J.; Fryberger, M. C.; George, A.; Percec, V. J. Org.
Chem. 2012, 77, 2885. (c) Zhang, N.; Hoffman, D. J.; Gutsche, N.;
Gupta, J.; Percec, V. J. Org. Chem. 2012, 77, 5956. (d) Jezorek, R. L.;
Zhang, N.; Leowanawat, P.; Bunner, M. H.; Gutsche, N.; Pesti, A. K. R.;
Olsen, J. T.; Percec, V. Org. Lett. 2014, 16, 6326.
(10) (a) Molander, G. A.; Shin, I. Org. Lett. 2013, 15, 2534. (b) Wang,
Z.-Y.; Ma, Q.-N.; Li, R.-H.; Shao, L.-X. Org. Biomol. Chem. 2013, 11,
7899.
(11) (a) Miyaura, N.; Suzuki, A. Chem. Rev. 1995, 95, 2457.
(b) Roughley, S. D.; Jordan, A. M. J. Med. Chem. 2011, 54, 3451.
(12) (a) O’Donovan, M. R.; Mee, C. D.; Fenner, S.; Teasdale, A.;
Phillips, D. H. Mutat. Res., Genet. Toxicol. Environ. Mutagen. 2011, 724, 1.
(b) Hansen, M. M.; Jolly, R. A.; Linder, R. J. Org. Process Res. Dev. 2015,
19, 1507.
(13) Denmark, S. E.; Ambrosi, A. Org. Process Res. Dev. 2015, 19, 982.
(14) (a) Nakao, Y.; Hiyama, T. Chem. Soc. Rev. 2011, 40, 4893.
(b) Sore, H. F.; Galloway, W. R. J. D.; Spring, D. R. Chem. Soc. Rev. 2012,
41, 1845.
Figure 4. Isolated yields of products for couplings of aryl sulfamates with
aryl silanolates. Conditions: silanolate (0.2 mmol), aryl sulfamate (0.1
mmol), Pd-RuPhos precatalyst (0.005 mmol), RuPhos (0.005 mmol),
toluene (1 mL), 110 °C, 8 hours. aPerformed on 1 mmol scale in relation
to aryl sulfamate. bSilanolate (0.3 mmol). Yields are the average of two
runs.
ASSOCIATED CONTENT
* Supporting Information
■
S
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.orglett.6b02330.
Experimental procedures and characterization data (PDF)
(15) (a) Denmark, S. E.; Chang, W.-T. T. Cross-Coupling with Silicon
Reagents: Alkenylsilanes. In Science of Synthesis: Cross Coupling and
Heck-Type Reactions; Molander, G. A., Ed.; Thieme: Stuttgart, 2013; Vol.
1, p 431. (b) Denmark, S. E.; Chang, W.-T. T. Cross-Coupling with
Silicon Reagents: Heteroarylsilanes. In Science of Synthesis: Cross
Coupling and Heck-Type Reactions; Molander, G. A., Ed.; Thieme:
Stuttgart, 2013; Vol. 1, p 495. (c) Denmark, S. E.; Chang, W.-T. T.
Cross-Coupling with Silicon Reagents: Arylsilanes. In Science of
Synthesis: Cross Coupling and Heck-Type Reactions; Molander, G. A.,
Ed.; Thieme: Stuttgart, 2013; Vol. 1, p 383. (d) Denmark, S. E. Cross-
Coupling Reactions of Organosilicon Compounds. In Metal-Catalyzed
Cross-Coupling Reactions; deMeijere, A., Brase, S., Oestreich, M., Eds.;
Wiley-VCH: Weinheim, 2013; Chapter 4. (e) Tymonko, S. A.; Smith, R.
C.; Ambrosi, A.; Denmark, S. E. J. Am. Chem. Soc. 2015, 137, 6192.
(f) Tymonko, S. A.; Smith, R. C.; Ambrosi, A.; Ober, M. H.; Wang, H.;
Denmark, S. E. J. Am. Chem. Soc. 2015, 137, 6200.
(16) (a) Denmark, S. E.; Smith, R. C.; Chang, W.-T. T.; Muhuhi, J. M.
J. Am. Chem. Soc. 2009, 131, 3104. (b) Denmark, S. E.; Baird, J. D.;
Regens, C. S. J. Org. Chem. 2008, 73, 1440. (c) Denmark, S. E.; Baird, J.
D. Tetrahedron 2009, 65, 3120. (d) Denmark, S. E.; Smith, R. C.;
Tymonko, S. A. Tetrahedron 2007, 63, 5730.
(17) Melvin, P. R.; Nova, A.; Balcells, D.; Dai, W.; Hazari, N.;
Hruszkewycz, D. P.; Shah, H. P.; Tudge, M. T. ACS Catal. 2015, 5, 3680.
(18) Martin, R.; Buchwald, S. L. Acc. Chem. Res. 2008, 41, 1461.
(19) Melvin, P. R.; Balcells, D.; Hazari, N.; Nova, A. ACS Catal. 2015,
5, 5596.
AUTHOR INFORMATION
Corresponding Author
■
*E-mail: nilay.hazari@yale.edu.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
This research was supported by the NIHGMS under Award No.
R01GM120162. P.R.M. and M.M.B. thank the NSF for support
as NSF Graduate Research Fellows. N.H. is a Camille and Henry
Dreyfus Foundation Teacher−Scholar.
REFERENCES
■
(1) (a) Marion, N.; Nolan, S. P. Acc. Chem. Res. 2008, 41, 1440.
(b) Valente, C.; Calimsiz, S.; Hoi, K. H.; Mallik, D.; Sayah, M.; Organ,
M. G. Angew. Chem., Int. Ed. 2012, 51, 3314. (c) Colacot, T. J, Ed. New
Trends in Cross-Coupling: Theory and Applications; RSC Catalysis Series
No. 21; The Royal Society of Chemistry: Cambridge, 2015; pp 1−864.
(2) (a) Gooßen, L. J.; Gooßen, K.; Stanciu, C. Angew. Chem., Int. Ed.
2009, 48, 3569. (b) Rosen, B. M.; Quasdorf, K. W.; Wilson, D. A.;
Zhang, N.; Resmerita, A.-M.; Garg, N. K.; Percec, V. Chem. Rev. 2011,
111, 1346. (c) Yu, D.-G.; Li, B.-J.; Shi, Z.-J. Acc. Chem. Res. 2010, 43,
1486. (d) Mesganaw, T.; Garg, N. K. Org. Process Res. Dev. 2013, 17, 29.
(e) Tobisu, M.; Chatani, N. Top. Organomet. Chem. 2012, 44, 35.
(f) Cornella, J.; Zarate, C.; Martin, R. Chem. Soc. Rev. 2014, 43, 8081.
(g) Tobisu, M.; Chatani, N. Acc. Chem. Res. 2015, 48, 1717.
(20) Kinzel, T.; Zhang, Y.; Buchwald, S. L. J. Am. Chem. Soc. 2010, 132,
14073.
(21) Brauer, D. J.; Krueger, C. Inorg. Chem. 1977, 16, 884.
(22) For references related to Hiyama reactions with aryl chlorides
using fluoride activators, see: Yuen, O. Y.; So, C. M.; Man, H. W.;
Kwong, F. Y. Chem. - Eur. J. 2016, 22, 6471 and references cited therein.
(3) Rappoport, Z. The Chemistry of Phenols; John Wiley & Sons:
Chichester, 2003.
(4) (a) Snieckus, V. Chem. Rev. 1990, 90, 879. (b) Hartung, C. G.;
Snieckus, V. Modern Arene Chemistry; Wiley-VCH: New York, 2002.
D
DOI: 10.1021/acs.orglett.6b02330
Org. Lett. XXXX, XXX, XXX−XXX