Palladium-catalyzed cross-coupling of aryl chlorides with O, N-chelate stabilized diarylborinates

Article abstract of DOI:10.1016/j.jorganchem.2017.05.013

A series of O, N-chelated diarylborinates have been prepared and tested as arylboron counterpart alternative to oxygen-labile diarylborinic acids in palladium catalyzed Suzuki coupling of aryl chlorides. 3-Dimethylaminopropyl diarylborinates (B-5a), featuring a six-membered O, N-chelated boron ring that was confirmed by single crystal X-ray diffraction, displayed a delicately balanced stability and reactivity. Their cross-coupling with structurally various aryl chlorides could be effected as efficiently as that of the parent diarylborinic acids by using 0.1～1mol% Pd(OAc)₂/IPr/P(OPh)₃ as catalyst system, to provide the corresponding biaryls in good to excellent yields.

Full text of DOI:10.1016/j.jorganchem.2017.05.013

Journal of Organometallic Chemistry 842 (2017) 54e58
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Palladium-catalyzed cross-coupling of aryl chlorides with O, N-chelate
stabilized diarylborinates
,
, **
Nan Zhang a, Chen Wang a, Gang Zou a *, Jie Tang b
a School of Chemistry & Molecular Engineering, East China University of Science & Technology, 130 Meilong Rd, Shanghai, China
b Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical
Processes, SCME, East China Normal University, 3663 North Zhongshan Rd Shanghai, China
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of O, N-chelated diarylborinates have been prepared and tested as arylboron counterpart
alternative to oxygen-labile diarylborinic acids in palladium catalyzed Suzuki coupling of aryl chlorides.
3-Dimethylaminopropyl diarylborinates (B-5a), featuring a six-membered O, N-chelated boron ring that
was confirmed by single crystal X-ray diffraction, displayed a delicately balanced stability and reactivity.
Their cross-coupling with structurally various aryl chlorides could be effected as efficiently as that of the
parent diarylborinic acids by using 0.1~1mol% Pd(OAc)2/IPr/P(OPh)3 as catalyst system, to provide the
corresponding biaryls in good to excellent yields.
Received 20 March 2017
Received in revised form
1 May 2017
Accepted 4 May 2017
Available online 6 May 2017
Keywords:
© 2017 Elsevier B.V. All rights reserved.
Cross-coupling
Diarylborinate
O, N-Chelate
Palladium
N-Heterocyclic carbene
1. Introduction
and applications as arylation reagents. Inspired by the great suc-
cesses achieved by Burke et al. [11] in finely tuning the stability and
Four-coordinate diarylborinates, in particular those bearing an
intramolecular B-N coordinate bond, are much more stable than
the corresponding three-coordinate ones [1]. In fact, the former, as
stable derivatives of diarylborinic acids, has been increasingly
found in pharmaceutical reagents [2] and advanced materials [3]
while the later has been proposed as active intermediates in bor-
inic acid catalyzed processes, e.g. aldol condensation [4], Mannich-
type reaction [5] and amidation [6]. More recently, the parent five-
membered O, N-chelated diarylborinate, 2-aminoethyl diphe-
nylborinate (2-APB), has been identified as a universal blocker of
transient receptor potential channels [7]. We have recently re-
ported that diarylborinic acids could be used as a cost-effective aryl
source in palladium and nickel catalyzed cross-coupling reactions
with aryl (pseudo)halides [8], carboxylic acids [9] and amides [10].
However, the coordinatively unsaturated diarylborinic acids are
sometimes oxygen-labile and prone to dehydration and proto-
deboronation, complicating their long-term storage, stoichiometry
reactivities of arylboronates via coordinative, electronic and steric
properties of boron center, we anticipate that it should be possible
to develop storage-stable and easy-to-handle diarylborinates to
replace diarylborinic acids as arylation reagents in transition metal-
catalyzed cross-couplings. Herein, we report palladium catalyzed
cross-coupling of aryl chlorides, which are the least reactive but
most practical aryl halides due to their low cost and wide avail-
ability, with a series of O, N-chelate stabilized diarylborinates,
among them 3-dimethylaminopropyl diarylborinates performed as
efficiently as diarylborinic acids.
2. Results and discussion
The cross-coupling of 4-acetylchlorobenzene (Cl-1) with 2-
aminoethyl diphenylborinate (2-APB, B-1) was tested at first un-
der the conditions that we had developed for N,N’-bis(2,6-
diisopropylphenyl) imidazol-2-ylidene (IPr) palladium-catalyzed
cross-coupling of aryl halides with free diarylborinic acids, 0.1mol
% Pd(OAc)2/IPr/P(OPh)3 (1/1/2, mol/mol) in the presence of 2equiv.
K3PO4.3H2O in tBuOH at 80 ꢀC by using a slightly excess aryl source
(B/Cl ¼ 0.55 mol/mol, 1.1equiv. with respect to phenyl group) [8b].
The desired cross-coupling product, 4-acetylbiphenyl (P-1), was
* Corresponding author.
** Corresponding author.
E-mail addresses: zougang@ecust.edu.cn (G. Zou), jtang@chem.ecnu.edu.cn
(J. Tang).
http://dx.doi.org/10.1016/j.jorganchem.2017.05.013
0022-328X/© 2017 Elsevier B.V. All rights reserved.

N. Zhang et al. / Journal of Organometallic Chemistry 842 (2017) 54e58
55
obtained in a low but promising yield (27%) (Scheme 1). Encour-
aged by the preliminary result, a couple of five/six-membered, O,
N-chelate stabilized diarylborinates (B-2~B-8) [1b,12-15] were
prepared by reaction of diarylborinic acids with representative N-
containing alcohols or acids, e.g. dimethylaminoethanol, glycine,
dimethyl glycine, pyridin-2-ylmethanol, picolinic acid, 3-(dime-
thylamino)propanol
and
quinolin-8-ol.
Resonances
at
4.45e11.92 ppm in 11B NMR spectra of these diarylborinates are
consistent with the O, N-chelated four-coordinate boron center
[1b,2c]. The characteristic absorption of B-N (1350-1310cm-1) in IR
spectra also confirmed the formation of O, N-chelated four-
coordinate boron center in these diarylborinates [16].
Scheme 2. The coupling of 4-acetylchlorobenzene with B-5a.
Reactivities of these diarylborinates in the model cross-coupling
reaction were investigated. The biaryl product P-1 could be ob-
tained in 91% and 98% yields, respectively, with 2-
been explored (Table 1). Similar to the reaction of free diarylboronic
acids, a large electronic effect was observed from aryl chlorides. For
example, aryl chlorides bearing an electron-deficient benzene ring
reacted smoothly with B-5a to give biaryl products in excellent
yields (Entries 1e9).
dimethylaminoethyl
diphenylborinate
(B-2)
and
3-
dimethylaminopropyl diphenylborinate (B-5a) as the aryl source
in the model reaction while the analogues B-2~B4 and B-6~B-8
performed poorly.
In fact, excellent yields for P-1 could still be obtained when the
catalyst loading was reduced to 0.3mol% or even 0.1mol% provided
that P(OPh)3 was increased to 5equiv. (0.5mol%) with respect to Pd/
IPr (0.1mol%) (Scheme 2). The high reactivity of the six-membered
O, N-chelated diphenylborinate (B-5a) may be attributed to the
steric hindrance and/or the so-called through-bond interactions
[1b].
Crystal structure of the most reactive diphenylborinate B-5a was
determined and confirmed the presence of the six-membered N, O-
chelate stabilized boron center (Fig. 1). The N/B coordinate bond
distance is 1.7095(17)Å in B-5a is significantly longer than previ-
ously reported data for the related five/six-membered O, N-
chelated diphenylborinates B-1, B-2 and 3-aminopropyl diphe-
nylborinate where the bond lengths range from 1.61 to 1.65 Å while
the B-O (1.4542(16)Å) bond length is in the normal range from 1.35
to 1.48 Å [1b,17]. The B-CPh bond lengths (1.6425(18) and 1.6265(18)
Å) are slightly longer than those in B-1 (1.620 and 1.613 Å), B-2
(1.627 and 1.614 Å) and 3-aminopropyl diphenylborinate (1.620
and 1.626 Å). The angles around the tetra-coordinated boron atom
are between 102.9(9)ꢀ and 113.8(10)ꢀ closed to tetrahedral angle
values.
However, reaction of electron-rich 4-(benzyloxy)phenyl chlo-
ride (Cl-11) with B-5a became rather sluggish under the model
reaction conditions to offer biaryl P-11 in just 11% yield although
the high yields could be restored in the reaction of electron-rich
aryl chlorides by using 1mol% catalyst loading under the other-
wise identical conditions (Entries 10e19). Obviously, steric hin-
drance from a small ortho-substituent in these electron-deficient
aryl chlorides could be overcome since the yields of biaryl products
just slightly decreased compared with those with a substituent at
para- or meta-positions. Compared with electron-deficient ones,
steric hindrance of electron-rich aryl chlorides affected their
coupling remarkably. For example, o-tolylchloride and o-methox-
ylphenyl chloride reacted to give biaryl products 2-methylbiphenyl
(P-13, 72%) and 2-phenylanisole (P-16, 62%), in significantly lower
yields than their para-isomers (Entries 12 and 15). The yield further
decreased to 42% in the reaction of 2,6-dimethylphenyl chloride
(Entry 13).
Scope and limitation of the palladium-catalyzed cross-coupling
of aryl chlorides with 3-dimethylaminopropyl diarylborinates have
Fig. 1. An ORTEP view of the molecular structure of B-5a. B(1)-O(1) 1.4542(16)Å, B(1)-
N(1) 1.7095(17)Å, B(1)-C(1) 1.6425(18)Å, B(1)-C(7) 1.6265(18)Å; O(1)-B(1)-C(7)
108.84(10)ꢀ, O(1)-B(1)-C(1) 112.19(10)ꢀ, C(7)-B(1)-C(1) 110.97(10)ꢀ, O(1)-B(1)-N(1)
102.86(9)ꢀ, C(7)-B(1)-N(1) 107.80(10)ꢀ, C(1)-B(1)-N(1) 113.76(10)ꢀ.
Scheme 1. The coupling of 4-acetylchlorobenzene with O, N-chelate stabilized
diarylborinates.

56
N. Zhang et al. / Journal of Organometallic Chemistry 842 (2017) 54e58
Table 1
3. Conclusion
Scope of the palladium-catalyzed cross-coupling of aryl halides with 3-
dimethylaminopropyl diarylborinates.a
In summary, a series of O, N-chelated diarylborinates with
typical N-containing alcohol or acid ligands have been prepared
and fully characterized by spectroscopy including 11B NMR and
single crystal X-ray diffraction, aiming to develop an easy-to-
handle and storage-stable alternative to free diarylborinic acids in
palladium-catalyzed Suzuki coupling of aryl chlorides. Although a
slightly larger electronic effect of diarylborinates was observed 3-
dimethylaminopropyl diarylborinates, in which the six-
membered O, N-chelate-stabilized boron ring appeared to be
crucial to delicately balance their stability and reactivity, performed
comparably to diarylborinic acids in cross-coupling with a wide
range of aryl chlorides. A variety of biaryls could be obtained in
good to excellent yields via the cross-coupling of 3-
dimethylaminopropyl diarylborinates with aryl chlorides cata-
lyzed by 0.1~1mol% Pd(OAc)2/IPr/P(OPh)3. These results clearly
indicated that diarylborinates with well-balanced stability and
reactivity could be effected by carefully tuning the structure of the
chelate ligand.
Entry
R1
R2
Cat (%)
Yield (%)b
1
2
3
4
5
6
7
8
o-Ac(Cl-2)
m-Ac(Cl-3)
o-CN(Cl-4)
m-CN(Cl-5)
H(B-5a)
H(B-5a)
H(B-5a)
H(B-5a)
H(B-5a)
H(B-5a)
H(B-5a)
H(B-5a)
H(B-5a)
H(B-5a)
H(B-5a)
H(B-5a)
H(B-5a)
H(B-5a)
H(B-5a)
H(B-5a)
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
1
1
1
1
1
1
1
1
1
83(P-2)
99(P-3)
92(P-4)
96(P-5)
95(P-6)
97(P-7)
87(P-8)
90(P-9)
p-CN(Cl-6)
p-CO2Me(Cl-7)
p-CHO(Cl-8)
p-NO2(Cl-9)
o-NO2(Cl-10)
p-OBn(Cl-11)
p-Me(Cl-12)
o-Me(Cl-13)
2,6-Me2(Cl-14)
p-OMe(Cl-15)
o-OMe(Cl-16)
p-NH2(Cl-17)
o-NH2(Cl-18)
2-Cl-Py(Cl-19)
3-Cl-Py(Cl-20)
p-Ac(Cl-1)
9
87(P-10)
98(11)c (P-11)
97(P-12)
72(P-13)
42(P-14)
95(P-15)
62(P-16)
91(P-17)
85(P-18)
83 (P-19)
85 (P-20)
91(P-21)
80(P-22)
93(P-23)
99(P-24)
95(P-25)
96(P-26)
82(P-27)
88(P-28)
92(P-29)
70(P-30)
94(P-31)
94(P-32)
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
4. Experimental section
H(B-5a)
H(B-5a)
H(B-5a)
General information: All reactions were carried out under ni-
trogen by using standard Schlenk techniques unless otherwise
stated. Commercially available chemicals were used as received.
Diarylboronic acids [8b], O, N-chelated diarylborinates [12,13,18]
and IPr$HCl [19], were prepared according to previously reported
procedures. Column chromatograph was performed on 200e300
mesh silica gal. 1H, 13C and 11B NMR spectra were recorded in CDCl3
or DMSO-d6 at ambient temperature. Chemical shifts in NMR are
1
p-Me(B-5b)
p-F(B-5f)
p-OMe(B-5j)
p-Me(B-5b)
m-Me(B-5c)
o-Me(B-5d)
m-F(B-5e)
p-F(B-5f)
o-Et(B-5g)
p-CF3(B-5h)
o-OMe(B-5i)
p-OMe(B-5j)
0.1
0.1
0.1
1
1
1
1
1
1
1
p-Ac(Cl-1)
p-Ac(Cl-1)
p-OBn(Cl-11)
p-OBn(Cl-11)
p-OBn(Cl-11)
p-OBn(Cl-11)
p-OBn(Cl-11)
p-OBn(Cl-11)
p-OBn(Cl-11)
p-OBn(Cl-11)
p-OBn(Cl-11)
reported in ppm (d), relative to the internal standard of tetrame-
thylsilane (TMS). The signals observed are described as s (singlet),
d (doublet), t (triplet), q (quartet), dd (double doublet), m (multi-
plets). The number of protons (n) for a given resonance is indicated
as nH. Coupling constants are reported as J in Hz. The organic
compounds were identified by 1H and 13C NMR (see Supporting
Information) [8a,8b,20e27]. All new compounds were further
characterized by HRMS.
1
1
a
Reaction conditions: aryl chloride
1 mmol; diarylborinate 0.55 mmol;
K3PO4$3H2O, 2 mmol (2equiv.); tBuOH, 5 mL.
b
Isolated yields.
0.1mol% cat used.
c
4.1. Synthesis of O, N-chelated diarylborinates
The electronic and steric influence of 3-dimethylaminopropyl
diarylborinates on their cross-coupling with aryl halides were
General procedure A: Diarylboronic acid (10 mmol) in EtOAc
(20 mL) was added ethanolamine (0.61 g, 10 mmol). The mixture
was stirred at room temperature for 2 h. Precipitates were collected
by filtration and dried to give O, N-chelated diarylborinates (B-1, B-
2 and B-4~B-8).
Procedure for B-3: To a solution of the diarylboronic acid
(10 mmol) in EtOH (20 mL) was added glycine (0.75 g, 10 mmol) in
H2O (5 mL). The mixture was stirred for 4 h at reflux before cooling
down to room temperature. Precipitates were collected by filtration
and dried in vacuum to give B-3.
also investigated. The steric influence from
a small ortho-
substituent on the benzene ring of diarylborinates B-5 was negli-
gible. For example, diarylborinates bearing an ortho-methyl (B-5d),
ethyl (B-5g) and methoxyl (B-5i) group reacted with 4-(benzyloxy)
phenyl chloride (Cl-11) similarly to their para-isomers (Entries 23,
25, 28, 30 and 31), giving the corresponding biaryl products P-26,
P-29 and P-31 in comparable yields. Although electronically
various diarylborinates (B-5) could react smoothly with both
electron-rich (Cl-11) and -deficient (Cl-1) aryl chlorides to offer
biaryls P-21~23 and P-24~P-32 in good to excellent yields (Entries
20e31), a larger electronic effect was observed from the diary-
lborinates in reaction with electron-rich aryl chlorides compared
with the free diarylborinic acids, which displayed a negligible
electronic influence on their coupling with aryl chlorides under
similar conditions [8b]. For example, the electron-deficient diary-
lborinates (B-5e, B-5f and B-5h) reacted with Cl-11 to give biaryls
in obviously lower yields (70e88%) than the electron-neutral and
-rich analogues (B-5b, B-5c and B-5j) (94e99%) (Entries 26, 27, 29
vs 23, 24, 31).
4.1.1. 3-((Bis(4-methylphenyl)boranyl)oxy)-N,N-dimethylpropan-1-
amine (B-5b)
White solid (2.83 g, 96% yield), mp 104e105 ꢀC, 1H NMR
(400 MHz, CDCl3)
4H), 3.74 (t, J ¼ 5.6 Hz, 2H), 3.00 (t, J ¼ 5.6 Hz, 2H), 2.43 (s, 6H), 2.24
(s, 6H), 1.78e1.72 (m, 2H). 13C NMR (100 MHz, CDCl3)
(ppm): 135.1,
133.3, 128.0, 126.8, 60.2, 58.5, 46.1, 24.6, 20.2. 11B NMR (128 MHz,
CDCl3)
(ppm): 14.38. HRMS (EI) m/z [M]þ calcd for C19H26BNO
295.2107, found 295.2104. IR (KBr)
(N/B) 1310 cmꢁ1
d
(ppm): 7.39 (d, J ¼ 8.0 Hz, 4H), 7.01 (d, J ¼ 7.6 Hz,
d
d
n
.

N. Zhang et al. / Journal of Organometallic Chemistry 842 (2017) 54e58
57
4.1.2. 3-((Bis(3-methylphenyl)boranyl)oxy)-N,N-dimethylpropan-
4.1.8. 3-((Bis(2-methoxyphenyl)boranyl)oxy)-N,N-dimethylpropan-
1-amine (B-5c)
1-amine (B-5i)
White solid (2.86 g, 97% yield), mp 132e134 ꢀC, 1H NMR
Yellow liquid (3.21 g, 98% yield), 1H NMR (400 MHz, CDCl3)
(400 MHz, CDCl3)
d
(ppm): 7.42 (s, 2H), 7.36 (d, J ¼ 7.2 Hz, 2H), 7.16
d
(ppm): 7.31e7.25 (m, 4H), 6.95e6.87 (m, 4H), 5.67 (s, 2H), 3.96 (t,
(t, J ¼ 7.2 Hz, 2H), 7.04 (d, J ¼ 7.2 Hz, 2H), 3.82 (t, J ¼ 5.6 Hz, 2H), 3.09
J ¼ 6.4 Hz, 2H), 3.83 (s, 6H), 3.76 (s, 6H), 3.08e3.01 (m, 2H). 13C NMR
(t, J ¼ 6.0 Hz, 2H), 2.53 (s, 6H), 2.31 (s, 6H), 1.86e1.81 (m, 2H). 13
C
(100 MHz, CDCl3) d(ppm): 136.4, 129.4, 120.9, 113.8, 109.7, 58.8,
NMR (100 MHz, CDCl3)
d(ppm): 136.2, 135.0, 131.4, 127.7, 127.0, 61.1,
55.2, 55.1, 45.4, 27.6. 11B NMR (128 MHz, CDCl3)
d(ppm): 13.31.
59.5, 47.1, 25.6, 21.8. 11B NMR (128 MHz, CDCl3)
HRMS (EI) m/z [M]þ calcd for C19H26BNO 295.2107, found 295.2106.
IR (KBr)
(N/B) 1310 cmꢁ1
d
(ppm): 11.27.
HRMS (ESI) m/z [Mþ1]þ calcd for C19H26BNO3 328.2084, found
328.2084. IR (KBr)
n .
(N/B) 1330 cmꢁ1
n
.
4.1.9. 3-((Bis(4-methoxyphenyl)boranyl)oxy)-N,N-dimethylpropan-
1-amine (B-5j)
4.1.3. 3-((Bis(2-methylphenyl)boranyl)oxy)-N,N-dimethylpropan-
1-amine (B-5d)
White solid (3.11 g, 95% yield), mp 114e115 ꢀC, 1H NMR
Yellow liquid (2.78 g, 94% yield), 1H NMR (400 MHz, CDCl3)
(400 MHz, CDCl3)
4H), 3.83 (t, J ¼ 5.6 Hz, 2H), 3.79 (s, 6H), 3.02 (t, J ¼ 5.6 Hz, 2H), 2.48
(s, 6H),1.85e1.80 (m, 2H). 13C NMR (100 MHz, CDCl3)
(ppm): 159.5,
135.9, 129.5, 112.8, 55.1, 55.0, 46.5, 26.5, 18.3. 11B NMR (128 MHz,
CDCl3)
(ppm): 12.86. HRMS (EI) m/z [M]þ calcd for C19H26BNO3
327.2006, found 327.2012. IR (KBr)
(N/B) 1310 cmꢁ1
d(ppm): 7.52 (d, J ¼ 8.8 Hz, 4H), 6.83 (d, J ¼ 8.8 Hz,
d
(ppm): 7.33 (d, J ¼ 7.6 Hz, 2H), 7.29e7.25 (m, 2H), 7.14 (t, J ¼ 8.0 Hz,
d
4H), 3.84 (s, 2H), 2.44 (s, 2H), 2.37 (s, 6H), 2.16 (s, 6H), 1.74 (t,
J ¼ 6.0 Hz, 2H). 13C NMR (100 MHz, CDCl3)
d(ppm): 141.9, 134.1,
129.8, 129.5, 124.9, 64.4, 58.3, 45.1, 28.3, 22.6. 11B NMR (128 MHz,
d
CDCl3)
d
(ppm): 11.67. HRMS (EI) m/z [M]þ calcd for C19H26BNO
(N/B) 1340 cmꢁ1
n
.
295.2107, found 295.2104. IR (KBr)
n
.
4.2. General procedure for Suzuki coupling reaction of aryl chlorides
with O, N-chelated diarylborinates
4.1.4. 3-((Bis(3-fluorophenyl)boranyl)oxy)-N,N-dimethylpropan-1-
amine (B-5e)
Under a N2 atmosphere, to a 10 mL dry flask were added aryl
chloride (1.0 mmol), O, N-chelated diarylborinates (0.55 mmol),
Pd(OAc)2 (0.1~1 mol%), IPr$Cl (0.1~1 mol%), P(OPh)3 (0.5~5 mol%),
K3PO4. H2O (2 mmol), and tBuOH (5 mL). The mixture was stirred at
80 ꢀC for a given time or monitored by TLC until the starting ma-
terial was completely consumed. The reaction mixture was diluted
with EtOAc (15 mL), followed by washing with H2O (2 ꢂ 10 mL). The
organic layer was dried over Na2SO4, filtered, and evaporated under
reduced pressure to give crude product, which was purified by
column chromatography on silica gel to afford product.
White solid (2.94 g, 97% yield), mp 130e131 ꢀC, 1H NMR
(400 MHz, CDCl3)
3.82 (t, J ¼ 5.6 Hz, 2H), 3.22 (t, J ¼ 6.0 Hz, 2H), 2.60 (s, 6H), 1.92e1.87
(m, 2H). 13C NMR (100 MHz, CDCl3)
d(ppm): 7.27e7.16 (m, 6H), 6.87e6.82 (m, 2H),
d
(ppm): 162.5 (d, J ¼ 242.9 Hz),
129.3 (d, J ¼ 2.2 Hz), 128.4 (d, J ¼ 7.1 Hz), 120.1 (d, J ¼ 18.0 Hz), 112.6
(d, J ¼ 21.0 Hz), 60.25, 59.9, 47.9, 24.6. 11B NMR (128 MHz, CDCl3)
d
(ppm): 6.34. HRMS (EI) m/z [M]þ calcd for C17H20BF2NO 303.1606,
found 303.1608. IR (KBr)
n .
(N/B) 1310 cmꢁ1
4.1.5. 3-((Bis(4-fluorophenyl)boranyl)oxy)-N,N-dimethylpropan-1-
amine (B-5f)
4.2.1. 4-Benzyloxy-30-fluorobiphenyl (P-27)
White solid (2.97 g, 98% yield), mp 122e123 ꢀC, 1H NMR
White solid (228 mg, 82% yield), mp 103e104 ꢀC, 1H NMR
(400 MHz, CDCl3)
4H), 3.77 (t, J ¼ 5.6 Hz, 2H), 3.06 (t, J ¼ 6.0 Hz, 2H), 2.54 (s, 6H),
1.88e1.83 (m, 2H). 13C NMR (100 MHz, CDCl3)
(ppm): 161.9 (d,
J ¼ 240.0 Hz), 135.5 (d, J ¼ 6.8 Hz), 113.7 (d, J ¼ 18.9 Hz), 60.4, 59.7,
47.8, 24.9. 11B NMR (128 MHz, CDCl3)
(ppm): 8.87. HRMS (EI) m/z
[M]þ calcd for C17H20BF2NO 303.1606, found 303.1605. IR (KBr)
(N/B) 1310 cmꢁ1
d(ppm): 7.49 (q, J ¼ 6.4 Hz, 4H), 6.94 (t, J ¼ 8.8 Hz,
(400 MHz, CDCl3)
7.41e7.30 (m, 5H), 7.25e7.21 (m, 1H), 7.04 (m, 2H), 7.00e6.95 (m,
1H), 5,10 (s, 2H). 13C NMR (100 MHz, CDCl3)
(ppm): 161.3 (d,
d(ppm): 7.51e7.48 (m, 2H), 7.44 (d, J ¼ 7.6 Hz, 2H),
d
d
J ¼ 244 Hz), 158.8, 143.1 (d, J ¼ 7.6 Hz), 136.9, 132.7 (d, J ¼ 2.4 Hz),
130.2 (d, J ¼ 8.4 Hz), 128.7, 128.2, 128.1, 127.5, 122.3 (d, J ¼ 2.7 Hz),
115.3, 113.7 (d, J ¼ 9.2 Hz), 113.4 (d, J ¼ 8.6 Hz), 70.1. HRMS (EI) m/z
[M]þ calcd for C19H15FO 278.1107, found 278.1108.
d
n
.
4.1.6. 3-((Bis(2-ethylphenyl)boranyl)oxy)-N,N-dimethylpropan-1-
4.3. X-ray crystallographic data
amine (B-5g)
Yellow liquid (3.17 g, 98% yield), 1H NMR (400 MHz, CDCl3)
The X-ray diffraction measurements of compound B-5a was
carried out using SC-XRD D8 VENTURE area-detector diffractom-
d
(ppm): 7.33e7.28 (m, 4H), 7.19 (d, J ¼ 7.2 Hz, 2H), 7.12 (t, J ¼ 7.6 Hz,
2H), 3.85 (s, 2H), 2.73 (q, J ¼ 7.2 Hz, 4H), 2.42 (t, J ¼ 7.2 Hz, 2H), 2.14
eter and using CuК
solved by SHELXT followed by successive refinements using the 4
scans method on F2 using SHELXL-2014.
a
radiation (
l
¼ 1.54178 Å). The structure was
(s, 6H), 1.77e1.71 (m, 2H), 1.15 (t, J ¼ 7.6 Hz, 6H). 13C NMR (100 MHz,
CDCl3) d(ppm): 148.4, 134.3, 129.5, 128.3, 128.2, 124.9, 64.4, 58.9,
-u
45.3, 29.1, 28.3, 16.7. 11B NMR (128 MHz, CDCl3)
d(ppm): 9.99. HRMS
(ESI) m/z [Mþ1]þ calcd for C21H31BNO 324.2499, found 324.2499. IR
4.4. Crystal data of B-5a
17H22BNO,
(KBr)
n .
(N/B) 1330 cmꢁ1
C
M
¼
267.17, Monoclinic,
a
¼
9.1048(2),
4.1.7. 3-((Bis(4-trifluoromethylphenyl)boranyl)oxy)-N,N-
dimethylpropan-1-amine (B-5h)
b ¼ 23.7982(6), c ¼ 7.2326(2) Å,
b
¼ 112.1410(10)ꢀ, V ¼ 1451.58(6)
Å3, Space group P21/n, Z ¼ 4, Dcalc ¼ 1.223 Mg/m3. Crystal size
0.05 ꢂ 0.04 ꢂ 0.03 mm3, qmax ¼ 66.68ꢀ, 11623 reflections measured,
Yellow liquid (3.87 g, 96% yield), 1H NMR (400 MHz, CDCl3)
d
(ppm): 7.60 (d, J ¼ 8.0 Hz, 4H), 7.45 (d, J ¼ 8.0 Hz, 4H), 3.78 (t,
2555 unique (Rint ¼ 0.0220),
m
¼ 0.568 mmꢁ1. The final R1 and wR2
J ¼ 4.8 Hz, 2H), 3.16 (s, 2H), 2.59 (s, 6H), 1.91e1.86 (m, 2H). 13C NMR
were 0.0414 and 0.1210 (I > 2\ s(I)), for 183 parameters.
(100 MHz, CDCl3)
d
(ppm): 134.9, 133.6, 127.7 (q, J ¼ 31.5 Hz), 124.9
(q, J ¼ 270.0 Hz), 123.4 (q, J ¼ 3.5 Hz), 60.8, 59.7, 45.5, 25.0. 11B NMR
Acknowledgements
(128 MHz, CDCl3) d
(ppm): 5.79. HRMS (EI) m/z [M]þ calcd for
C
19H20BF6NO 403.1542, found 403.1543. IR (KBr)
n
(N/B)
We are grateful for financial support provided by the National
Natural Science Foundation of China (21472041) and National Key
1330 cmꢁ1
.

58
N. Zhang et al. / Journal of Organometallic Chemistry 842 (2017) 54e58
[4] [a] H.C. Brown, K. Ganesan, R.K. Dhar, J. Org. Chem. 58 (1993) 147e153;
[b] K. Ganesan, H.C. Brown, J. Org. Chem. 59 (1994) 7346e7352;
Technology R&D Program, the Ministry of Science and Technology
of China (2015BAK44B00).
[c] J.L.-Y. Chen, V.K. Aggarwal, Angew. Chem. Int. Ed. 53 (2014) 10992e10996.
[5] Y. Tanaka, T. Hasui, M. Suginome, Synlett 8 (2008) 1239e1242.
ꢀ
[6] [a] B. Velasco, J.G. Trujillo-Ferrara, L.H.F. Castillo, R. Miranda, L.E. Sanchez-
Appendix A. Supplementary data
Torres, Life Sci. 80 (2007) 1007e1013;
[b] B. Velasco-Bejarano, J. Trujillo-Ferrara, R. Miranda, Synlett
921e924;
[c] T.M. El Dine, J. Rouden, J. Blanchet, Chem. Commun. 51 (2015)
16084e16087.
6 (2007)
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.jorganchem.2017.05.013.
[7] C.K. Colton, M.X. Zhu, Hepatology 179 (2007) 173e187.
[8] [a] H. Ke, X. Chen, G. Zou, J. Org. Chem. 79 (2014) 7132;
[b] X. Chen, H. Ke, Y. Chen, C. Guan, G. Zou, J. Org. Chem. 77 (2012) 7572.
[9] S. Si, C. Wang, N. Zhang, G. Zou, J. Org. Chem. 81 (2016) 4364e4370.
[10] X. Li, G. Zou, J. Organomet. Chem. 794 (2015) 136e145.
[11] [a] J. Li, A.S. Grillo, M.D. Burke, Acc. Chem. Res. 48 (2015) 2297e2307;
[b] E.P. Gillis, M.D. Burke, Aldrichimica Acta 42 (2009) 17e27;
[c] A.J.J. Lennox, G.C. Lloyd-Jones, Chem. Soc. Rev. 43 (2014) 412e443.
[12] L. Marciasini, B. Cacciuttolo, M. Vaultier, M. Pucheault, Org. Lett. 17 (2015)
3532e3535.
References
[1] [a] H. Weidmann, H.K. Zimmerman, Liebigs Ann. 619 (1958) 28e35;
ꢀ
ꢀ
[b] N. Farfan, D. Castillo, P. Joseph-Nathan, R. Contreras, L.v. Szentpaly, J. Chem.
Soc. Perkin Trans. 2 (1992) 527e532;
[c] N. Farfan, R. Contreras, J. Chem. Soc. Perkin Trans. 2 (1988) 1787.
ꢀ
[2] [a] S. Ozaki, A.Z. Suzuki, P.O. Bauer, E. Ebisui, K. Mikoshiba, Biochem. Biophys.
Res. Commum 441 (2013) 286e290;
[b] S.J. Baker, T. Akama, Y.-K. Zhang, V. Sauro, C. Pandit, R. Singh, M. Kully,
J. Khan, J.J. Plattner, S.J. Benkovic, V. Lee, K.R. Maples, Bioorg. Med. Chem. Lett.
16 (2006) 5963e5967;
[13] A. Hofer, G. Kovacs, A. Zappatini, M. Leuenberger, M.A. Hediger, M. Lochner,
Bioorg. Med. Chem. 21 (2013) 3202e3212.
[c] A. Hofer, G. Kovacs, A. Zappatini, M. Leuenberger, M.A. Hediger, M. Lochner,
Bioorg. Med. Chem. 21 (2013) 3202e3213;
[14] C.J. Strang, E. Henson, Y. Okamoto, M.A. Paz, P.M. Gallop, Anal. Biochem. 178
(1989) 276e286.
[d] K. Song, H. Wang, G.B. Kamm, J. Pohle, F.C. Reis, P. Heppenstall, H. Wende,
J. Siemens, Science 353 (2016) 1393e1398;
[15] E. Hohaus, F. Umland, Chem. Ber. 102 (1969) 4025e4031.
[16] [a] A. Kilic, F. Alcay, M. Aydemir, M. Durgun, A. Keles, A. Baysal, Spectrochim.
Acta Part A 142 (2015) 62e72;
[b] L.J. Bellamy, W. Gerrard, M.F. Lappert, R.L. Williams, J. Chem. Soc. (1958)
2412e2415.
[17] [a] S.J. Rettig, J. Trotter, Can. J. Chem. 54 (1976) 3130e3141;
[b] S.J. Rettig, J. Trotter, Can. J. Chem. 61 (1983) 2334e2340.
[18] J.L. Delarue, R.L. Fallard, FR M3036, 1965.
[e] J.M. Araujo-Alvarez, J.G. Trujillo-Ferrara, D. Ponce-Franco, J. Correa-
Basurto, A. Delgado, E. Querejeta, Chirality 23 (2011) 429e437;
[f] S.J. Benkovic, S.J. Baker, M.R.K. Alley, Y.-H. Woo, Y.-K. Zhang, T. Akama,
W. Mao, J. Baboval, P.T.R. Rajagopalan, M. Wall, L.S. Kahng, A. Tavassoli,
L. Shapiro, J. Med. Chem. 48 (2005) 7468e7476;
[g] C.-H. Tan, P.A. McNaughton, Nature 536 (2016) 460e478.
€
[3] [a] F. Jakle, Chem. Rev. 110 (2010) 3985e4022;
[19] J. Huang, S.P. Nolan, J. Am. Chem. Soc. 121 (1999) 9889e9890.
[20] P.D. Stevens, J. Fan, H.M.R. Gardimalla, M. Yen, Y. Gao, Org. Lett. 7 (2005)
2085e2088.
€
[b] F. Jakle, Coord. Chem. Rev. 250 (2006) 1107e1121;
[c] M. Rodríguez, J.L. Maldonado, G. Ramos-Ortíz, O. Domínguez, M.E. Ochoa,
ꢀ
R. Santillan, N. Farfan, M.-A. Meneses-Nava, O. Barbosa-García, Polyhedron 43
[21] R.-J. Tang, Q. He, L. Yang, Chem. Commun. 51 (2015) 5925e5928.
(2012) 194e200;
€
[22] R. Bandari, T. Hoche, A. Prager, K. Dirnberger, M.R. Buchmeiser, Chem. Eur. J.
ꢀ
ꢀ
[d] V.F. Pais, P. Ramírez-Lopez, A. Romero-Arenas, D. Collado, F. Najera,
16 (2010) 4650e4658.
ꢀ
ꢀ
E. Perez-Inestrosa, R. Fernandez, J.M. Lassaletta, A. Ros, U. Pischel, J. Org. Chem.
81 (2016) 9605e9611;
[23] L. Caron, L.-C. Campeau, K. Fagnou, Org. Lett. 10 (2008) 4533e4536.
[24] L. Ackermann, H.K. Potukuchi, A. Althammer, R. Born, P. Mayer, Org. Lett. 12
(2010) 1004e1007.
[25] E. Alacid, C. Najera, Org. Lett. 10 (2008) 5011e5014.
[26] A. Schmidt, A. Rahimi, Chem. Commun. 46 (2010) 2995e2997.
[27] V. Colombel, M. Presset, D. Oehlrich, F. Rombouts, G.A. Molander, Org. Lett. 14
(2012) 1680e1683.
[e] Z. Zhang, Z. Zhang, K. Ye, J. Zhang, H. Zhang, Y. Wang, Dalton Trans. 44
(2015) 14436e14443;
[f] Z. Zhang, H. Zhang, C. Jiao, K. Ye, H. Zhang, J. Zhang, Y. Wang, Inorg. Chem.
54 (2015) 2652e2659;
€
[g] F. Cheng, E.M. Bonder, F. Jakle, Macromolecules 45 (2012) 3078e3085;
€
[h] F. Cheng, E.M. Bonder, S. Salem, F. Jakle, Macromolecules 46 (2013)
2905e2915.