N-Arylation of Carbamates through Photosensitized Nickel Catalysis

Article abstract of DOI:10.1021/acs.joc.8b02182

A highly efficient method of visible light mediated Ni(II)-catalyzed photoredox N-arylation of Cbz-amines/Boc-amines with aryl electrophiles at room temperature is reported. The methodology provides a common access to a wide variety of N-aromatic and N-heteroaromatic carbamate products that find use in the synthesis of several biologically active molecules and provides a distinct advantage over traditional palladium-catalyzed Buchwald reaction.

Full text of DOI:10.1021/acs.joc.8b02182

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Article
N-Arylation of Carbamates through Photosensitized Nickel Catalysis.
Leleti Rajender Reddy, Sharadsrikar Kotturi, Yogesh Waman, Vudem
Ravinder Reddy, Chirag Patel, Ajinath Kobarne, and Sasikumar Kuttappan
J. Org. Chem., Just Accepted Manuscript • Publication Date (Web): 09 Oct 2018
Downloaded from http://pubs.acs.org on October 9, 2018
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N-Arylation of Carbamates through Photosensitized Nickel
Catalysis.
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Leleti Rajender Reddy,* Sharadsrikar Kotturi, Yogesh Waman, Vudem Ravinder Reddy, Chirag
Patel, Ajinath Kobarne and Sasikumar Kuttappan.
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Piramal Discovery Solutions, Pharmaceutical Special Economic Zone, Sarkhej Bavla Highway,
Ahmedabad, Gujarat 382213, India.
rajender.leleti@piramal.com
Cbz-NH2
NHBoc
NHCbz
or
Br
Ir, Ni
or
+
Blue LED
Boc-NH2
room temperature
broad FG tolerance
user friendly and scalable
inexpensive and ready available Cbz-amine
or Boc-amine
easily removable protecting groups
Abstract
A highly efficient method of visible light mediated Ni (II) catalyzed photoredox N-arylation of
Cbz-amines / Boc-amines with aryl electrophiles at room temperature is reported. The
methodology provides a common access to a wide variety of N-aromatic and N-heteroaromatic
carbamate products that find use in the synthesis of several biologically active molecules and
provides a distinct advantage over traditional palladium catalysed Buchwald reaction.
Introduction
Visible light mediated photoredox catalysis has recently emerged as a powerful activation strategy
for the discovery and invention of new organic transformations affording valuable molecules in a
safe, inexpensive, non-polluting, and thus potentially sustainable manner.1 Professor Deronzier,2
reported the first synthetic application of ruthenium photocatalysted Pschorr-type transformation
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via single electron transfer (SET) process. In recently, several groups started reporting the direct
photoexcitation of transition-metal catalyzed synthetic transformation to demonstrate this
paradigm.3 In particularly, Professor MacMillan’s sophisticated report on C-N bond formation of
aryl bromide with amines using Ni(II) salts and photoredox catalysis is the best alternative for
Buchwald–Hartwig reaction.4 Later, Professor MacMillan also published the N-arylation of
sulfonamides with aryl electrophiles via photosensitized Ni (II) catalysis.5 Inspired by the work of
Professor MacMillan, we reasoned that N-arylation / heteroarylation of carbamates through
photosensitized nickel catalysis could be a viable alternative for Buchwald-Hartwig N-arylation of
carbamates cross-coupling reaction (Scheme 1).6 Herein, we disclose the N-arylation /
heteroarylation of carbamates under Ni (II) catalyzed photoredox conditions.
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Scheme 1. Nickel-catalyzed of N-arylation of carbamates.
a) MacMillan's work for Photocatalysed Approach to Amination of Aryl Halides
H
R1
Br
N
Ir, Ni
H2N
R1
+
Blue LED
b) MacMillan's work for Photocatalysed Approach to Sulfonamidation of Aryl Halides
H
N
R1
Br
O
O
R1
Ir, Ni
S
S
+
H2N
O
O
Blue LED
c)
This work for Photocatalysed Approach to Carboamidation of Aryl / Hetereoaryl Halides
Cbz-NH2
NHBoc
NHCbz
or
Br
Ir, Ni
or
Boc-NH2
1
+
Blue LED
4
3
2
room temperature
broad FG tolerance
user friendly and scalable
inexpensive and ready available Cbz-amine
or Boc-amine
easily removable protecting groups
Results and discussion
At the outset of our investigation, we chose the 3-bromobenzonitrile (2a) and Cbz-amine (1a) as
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our model substrates. We began studying the proposed C-N bond formation reaction of 3-
bromobenzonitrile (2a) with Cbz-amine (1a) with emphasis on the development of a user-friendly
and scalable method. Fortunately, we found that the commercial bench-stable precatalyst systems
Ir(ppy)2(bpy)PF6 and NiCl2·glyme with 4,4’-di-t-butyl-2,2’-bipyridine ligand (dtbbpy) combined
with two equivalents of base (tetramethylguanidine, TMG) in CH3CN under irradiation with blue
LED (34 W) enabled the aryl amine (3a) in 93% yield (Table 1, entry 1). Based on the control
experiments, it has been found that both nickel and blue light presence were vital for the product
formation (Table 1). It has been also noticed that in the absence of photocatalyst, trace quantity
(<5%) of product was formed under direct irradiation of blue LED light. We observed that
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Ir(ppy)2(bpy)PF6 gives better results compared to
Ir[dF(CF3)ppy]2-(dtbbpy)PF6 and
Ru(bpy)3(PF6)2 (Table-2, entries 1, 3 and 4). In a similar manner NiCl2.glyme gives superior
results compared to Ni(cod)2 (Table 1, entries 1 and 2). While it could be advantageous to employ
aryl iodides or chlorides as substrates in these transformations, we observed that aryl bromide is
providing the better yield compare to the aryl chloride and aryl iodide (Table 2, entries 3 to 5).
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Table 1 Controlled experiments for N-arylation of Cbz-amine.
5
O
6
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9
Br
Ir(ppy)2(bpy)PF6
NiCl2·glyme, dtbbpy, TMG
HN
O
Ph
O
+
Ph
O
NH2
CH3CN, 23 oC, 48 h
CN
CN
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34 W Blue LED
1a
2a
3a
Entry
Conditionsb
Yield (%)a
93
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3
4
5
As mentioned above conditions
without light
No product
No product
<5
without Nickel catalyst
without photocatalyst
without photocatalyst and light
No product
a Isolated yield. bConducted with 0.05 mol% of Ir(ppy)2(bpy)PF6, 5.0 mol % of NiCl2·glyme,
1.0 equiv of aryl bromide, 1.5 equiv of Cbz-amine and 1.5 equiv of tetramethylguanidine.
With optimal reaction conditions for CN bond formation in hand, we then examined the
flexibility of the substrate scope of the photocatalytic reaction. Interestingly several electron-
neutral aryl halides and electron-rich halides delivered excellent yields (7593%) (Table-3). We
obtained excellent yields (9094%) with a variety of electron-deficient aryl electrophiles such as
p-cyano, p-methyl ester and p-trifluoromethyl derivatives with Cbz-amine (Table 3). Furthermore,
a wide range of heteroaromatic halides such as pyrimidine, pyridine and benzothiophene
derivatives were successfully coupled with Cbz-amine with good yields (7380%).
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Table 2 Optimization of N-arylation reaction conditions.
5
O
6
7
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9
X
Photocatalyst
Nickel Catalyst, dtbbpy, TMG
HN
O
Ph
O
+
Ph
O
NH2
CH3CN, 23 oC, 48 h
CN
CN
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34 W Blue LED
3a
1a
2
, X = Cl, Br, I
Entry
2
Photocatalystb
Ni catalyst
Yield (%)a
93
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6
X = Br
X = Br
X = Br
X = Br
X = I
Ir(ppy)2(bpy)PF6
NiCl2·glyme
Ir(ppy)2(bpy)PF6
Ni(cod)2
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Ir[dF(CF3)ppy]2-(dtbbpy)PF6 NiCl2·glyme
Ru(bpy)3(PF6)2
Ir(ppy)2(bpy)PF6
Ir(ppy)2(bpy)PF6
NiCl2·glyme
NiCl2·glyme
NiCl2·glyme
X = Cl
aIsolated yield. bConducted with 0.05 mol% of Ir(ppy)2(bpy)PF6, 5.0 mol % of NiCl2·glyme, 1.0 equiv of
aryl bromide, 1.5 equiv of Cbz-amine and 1.5 equiv of tetramethylguanidine.
Encouraged by these results, we turned our attention to the Boc-amine. Under optimal conditions
the Boc-amine was reacted with a large number of aryl halide electrophiles such as an electron-
neutral, electron-rich, electron-deficient and heteroaryl halides to obtain the Boc protected
arylamines 4 in good to excellent yields (Table 4). Finally, we have also checked reaction of the
benzamide (1c) with 4-bromobenzonitrile (2g) under optimal conditions and obtained benzoyl
protected 4r in excellent yield (92%) (Scheme 2).
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Table 3. Scope of N-arylation / heteroarylation of Cbz-amine.a,b
5
6
7
8
O
Br
Ir(ppy)2(bpy)PF6
NiCl2·glyme, dtbbpy, TMG
HN
O
Ph
O
+
9
Ph
O
NH2
CH3CN, 23 oC, 48 h
34 W Blue LED
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3
1a
2
NHCbz
NHCbz
NHCbz
NHCbz
Me
CN
Ph
3a
3b
3c
3d
Yield : 93 %
Yield : 79 %
Yield : 82 %
Yield : 85 %
NHCbz
NHCbz
NHCbz
NHCbz
OMe
OMe
CN
3g
COOMe
3h
3f
3e
Yield : 92%
Yield : 75%
Yield : 94 %
Yield : 79 %
NHCbz
NHCbz
NHCbz
NHCbz
N
N
F
F3C
CF3
NMe2
CF3
3l
3i
3j
3k
Yield : 77 %
Yield : 90 %
Yield : 91 %
Yield : 75 %
NHCbz
NHCbz
N
NHCbz
N
NHCbz
N
N
S
CN
Me
3n
Yield : 76 %
3o
Yield : 73 %
3m
Yield : 74 %
3p
Yield : 78 %
aIsolated yield. bConducted with 0.05 mol% of Ir(ppy)2(bpy)PF6, 5.0 mol % of NiCl2·glyme, 1.0 equiv of aryl bromide,
1.5 equiv of Cbz-amine and 1.5 equiv of tetramethylguanidine.
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Table 4 Scope of N-arylation / heteroarylation of Boc-amine.
5
6
7
8
O
Br
Ir(ppy)2(bpy)PF6
NiCl2·glyme, dtbbpy, TMG
HN
O
O
+
9
O
NH2
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CH3CN, 23 oC, 48 h
34 W Blue LED
4
1b
2
NHBoc
NHBoc
NHBoc
NHBoc
NHBoc
CN
Ph
4d
Me
OMe
4e
4c
4a
4b
Yield : 79 %
Yield : 81 %
Yield : 90 %
Yield : 74 %
Yield : 75 %
NHBoc
CN
NHBoc
NHBoc
NHBoc
NHBoc
N
F
F3C
CF3
COOMe
CF3
4g
4j
4i
4l
4h
Yield : 91 %
Yield : 92 %
Yield : 89 %
Yield : 75 %
Yield : 90%
NHBoc
NHBoc
NHBoc
N
N
N
Me
S
4o
Yield : 71 %
4n
4p
Yield : 82 %
Yield : 74 %
aIsolated yield. bConducted with 0.05 mol% of Ir(ppy)2(bpy)PF6, 5.0 mol % of NiCl2·glyme, 1.0 equiv of aryl
bromide, 1.5 equiv of Cbz-amine and 1.5 equiv of tetramethylguanidine.
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Based on previous reports4,5,7 of the mechanism of photoredox catalysis, we envisioned that visible light
mediated Ni (II) catalyzed N-arylation of carbamate (1) with aryl electrophiles (2) is shown in Figure 1.
The catalysis process starts with oxidative addition of Ni0 complex 5 into aromatic halide 2 to from NiII-
aryl complex 6. The ligand exchange of NiII-aryl complex 6 with Cbz-amine (1) might generates NiII-
aromatic amido complex 7. Simultaneously, blue light irradiation of IrIII photocatalyst 8 would generate
triplet excited *IrIII (9). The NiII-aryl complex 6 and excited-state Ir system 9 might go through triplet–
triplet energy transfer to procedure excited nickel species 10. The formed triplet-excited-state complex 10
would readily go through a reductive elimination step to deliver N-aryl carbamate product 3 and restore Ni0
catalyst 5.
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ArBr
2
L
L
L
L
Ni0
5
L
L
Br
Ar
NiII
Ar NHCbz
3
6
Nickel Catalytic Cycle
Cbz-amine
1
*
L
L
NHCbz
Ar
NiII
L
NHCbz
Ar
NiII
L
10
7
Triplet
ecited state
9
Singlet
ground state
III
IrIII
S0
*
Ir
Photosensitization
Cycle
T1
8
Blue LED
Figure 1. Proposed catalytic cycle.
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Scheme 2. Reaction of benzamide with 4-bromobenzonitrile.
5
6
7
8
O
Br
O
Ir(ppy)2(bpy)PF6
NiCl2·glyme, dtbbpy, TMG
HN
NH2
+
9
CH3CN, 23 oC, 48 h
34 W Blue LED
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CN
2g
1c
CN
4r
Conclusions
In conclusion, we have demonstrated a photoredox catalysis of N-arylation of Cbz-amine/ Boc-
amine with aromatic bromides / hetero aromatic bromides under exceptionally mild conditions.
The methodology provides a distinct advantage over traditional palladium catalysed Buchwald
reaction.
Experimental Section
General Information. All the reactions were performed under nitrogen gas in glasswares that was
flame-dried and equipped with a magnetic stirring bar. Thin-layer chromatography (TLC) was
performed using silica gel 60 F254 pre-coated plates (0.25 mm). All the reactions monitored by
the TLC analysis (single spot/ two solvent systems) using a UV lamp or PMA for detection
purposes. Flash chromatography was performed using silica gel (40 μm particle size). 1H and 13C
NMR spectra were recorded on a FT-NMR spectrometer at 400 and 100 MHz, respectively. The
aryl bromides/heteroaryl bromides, Boc amine/Cbz amine, Ir[dF(CF3)ppy]2-(dtbbpy)PF6,
Ru(bpy)3(PF6)2, Ir(ppy)2(bpy)PF6, NiCl2.glyme, Ni(cod)2, 4,4’-di-t-butyl-2,2’-bipyridine (dtbbpy)
and tetramethylguanadine (TMG) were purchased from commercial source and used as received.
All solvents were purchased from Aldrich and used without further purification. All the products
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(3a-q and 4a-r) were characterized by comparing with literature known data or commercially
available reference standards.
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General procedure (GP):
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To an oven dried 10 mL vial, aryl bromide (1.0 mol, 1.0 equiv.), carbamate (1.5 mol, 1.5 equiv.)
and acetonitrile were added. The reaction mixture was degassed with Argon (for 15 minutes) then
TMG (1.5 mol, 1.50 equiv.), dtbbpy (0.1 mol, 0.1 equiv.) NiCl2⋅glyme (0.05 mol, 0.05 equiv.) and
Ir(ppy)2(dtbbpy)PF6 (0.005 mol, 0.005 equiv.) were added. The vial was irradiated with 32 W blue
LED for 48 h at room temperature. After completion of the reaction, the reaction mixture was
concentrated to dry ness and crude material was purified by column chromatography (silica gel,
10% Ethyl acetate in Hexanes) to afford the pure compound 3 and 4.
Benzyl (3-cyanophenyl)carbamate (3a): Following the general procedure (GP), the reaction of 3-
bromobenzonitrile 2a (182 mg, 1.0 mol) with benzyl carbamate (226 mg, 1.5 mol), tetramethyl
guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6 (5.6 mg,
0.005 mol) afforded 3a as white solid (234 mg, 93%). The compound data was matched with
commercially available compound. 1H NMR (400 MHz, CDCl3) δ 7.82 (s, 1H), 7.61-7.55 (m, 1H),
7.49-7.28 (m, 7H), 6.99 (bs, 1H), 5.23 (s, 2H). 13C NMR (100 MHz, CDCl3) δ ppm 153.0, 138.7,
135.5, 129.9, 128.7, 128.6, 128.4, 126.9, 122.6, 121.5, 118.5, 113.0, 67.5.
Benzyl phenylcarbamate (3b): Following the general procedure (GP), the reaction of
bromobenzene 2b (157 mg, 1.0 mol) with benzyl carbamate (226 mg, 1.5 mol), tetramethyl
guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6 (5.6 mg,
0.005 mol) afforded 3b as white solid (179 mg, 79%). The compound matched previously reported
characterization data.8a 1H NMR (400 MHz, CDCl3) δ 7.46-7.28 (m, 9H), 7.12-7.06 (m, 1H), 6.76
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(bs, 1H), 5.23 (s, 2H). C NMR (100 MHz, CDCl3) δ ppm 153.3, 137.7, 136.0, 129.1, 128.6,
5
6
128.4, 128.3, 123.5,118.6, 67.0.
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9
Benzyl m-tolylcarbamate (3c): Following the general procedure (GP), the reaction of 1-bromo-3-
methylbenzene 2c (171 mg, 1.0 mol) with benzyl carbamate (226 mg, 1.5 mol), tetramethyl
guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6 (5.6 mg,
0.005 mol) afforded 3c as white solid (197 mg, 82%). The compound matched previously reported
characterization data.8b 1H NMR (400 MHz, CDCl3) δ 7.51-7.30 (m, 5H), 7.28-7.14 (m, 3H), 6.94-
6.88 (m, 1H), 6.68 (bs, 1H), 5.22 (s, 2H), 2.35 (s, 3H).13C NMR (100 MHz, CDCl3) δ ppm 153.3,
139.0, 137.6, 136.0, 128.9, 128.6, 128.3, 128.3,124.3, 119.3, 115.7, 66.9, 21.5.
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Benzyl [1,1'-biphenyl]-3-ylcarbamate (3d): Following the general procedure (GP), the reaction of
3-bromo-1,1'-biphenyl 2d (233 mg, 1.0 mol) with benzyl carbamate (226 mg, 1.5 mol), tetramethyl
guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6 (5.6 mg,
0.005 mol) afforded 3d as white solid (257 mg, 85%). The compound matched previously reported
characterization data.8c 1H NMR (400 MHz, CDCl3) δ 7.81-7.56 (m, 3H), 7.48-7.19 (m, 11H), 6.83
(s, 1H), 5.25 (s, 2H). 13C NMR (100 MHz, CDCl3) δ ppm 153.3, 142.2, 140.7, 138.2, 136.0, 129.4,
128.7, 128.6, 128.4, 128.3, 127.5, 127.2, 122.4, 117.5, 67.1.
Benzyl (4-methoxyphenyl)carbamate (3e): Following the general procedure (GP), the reaction of
1-bromo-4-methoxybenzene 2e (187 mg, 1.0 mol) with benzyl carbamate (226 mg, 1.5 mol),
tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6
(5.6 mg, 0.005 mol) afforded 3e as white solid (203 mg, 79%). The compound matched previously
reported characterization data.8d 1H NMR (400 MHz, CDCl3) δ 7.46-7.28 (m, 7H), 6.92-6.86 (m,
2H), 6.67 (bs, 1H), 5.23 (s, 2H), 3.82 (s, 3H). 13C NMR (100 MHz, CDCl3) δ ppm 156.0, 153.7,
136.2, 130.8, 128.6, 128.3, 120.7, 114.3, 66.9, 55.5.
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Benzyl (3-methoxyphenyl)carbamate (3f): Following the general procedure (GP), the reaction of
1-bromo-3-methoxybenzene 2f (187 mg, 1.0 mol) with benzyl carbamate (226 mg, 1.5 mol),
tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6
(5.6 mg, 0.005 mol) afforded 3f as white solid (192 mg, 75%). The compound matched previously
reported characterization data.8e 1H NMR (400 MHz, CDCl3) δ 7.52-7.34 (m, 5H), 7.28-7.15 (m,
2H), 6.95-6.85 (m, 1H), 6.84-6.71 (m, 1H), 6.7-6.56 (m, 1H), 5.22 (s, 2H), 3.81 (s, 3H). 13C NMR
(100 MHz, CDCl3) δ ppm 160.2, 153.4, 139.0, 135.9, 129.7, 128.6, 128.4, 128.3, 110.8, 109.3,
104.3, 67.0, 55.2.
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Benzyl (4-cyanophenyl)carbamate (3g): Following the general procedure (GP), the reaction of 4-
Bromo benzonitrile 2g (182 mg, 1.0 mol) with benzyl carbamate (226 mg, 1.5 mol), tetramethyl
guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6 (5.6 mg,
0.005 mol) afforded 3g as white solid (236 mg, 94%). The compound matched previously reported
characterization data.8f 1H NMR (400 MHz, CDCl3) δ 7.63 (d, J = 8.8 Hz, 2H), 7.55 (d, J = 8.4 Hz,
2H), 7.48-7.40 (m, 5H), 6.93 (bs, 1H), 5.26 (s, 2H). 13C NMR (100 MHz, CDCl3) δ ppm, 152.7,
142.0, 135.4, 133.4, 128.7, 128.7, 128.4, 118.3, 106.4, 67.6.
Methyl 4-(((benzyloxy)carbonyl)amino)benzoate (3h): Following the general procedure (GP), the
reaction of Methyl 4-bromobenzoate 2h (215 mg, 1.0 mol) with benzyl carbamate (226 mg, 1.5
mol), tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and
Ir(ppy)2(dtbbpy)PF6 (5.6 mg, 0.005 mol) afforded 3h as white solid (262 mg, 92%). The compound
matched previously reported characterization data.8g 1H NMR (400 MHz, CDCl3) δ 8.03 (d, J =
13
8.0 Hz, 2H), 7.58-7.37 (m, 7H), 6.99 (bs, 1H), 5.25 (s, 2H), 3.93 (s, 3H). C NMR (100 MHz,
CDCl3) δ ppm 166.6,152.9, 142.1, 135.7, 130.9, 128.7, 128.5, 128.4, 124.9, 117.6, 67.4, 52.0.
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Benzyl (4-(trifluoromethyl)phenyl)carbamate (3i): Following the general procedure (GP), the
reaction of 1-bromo-4-(trifluoromethyl)benzene 2i (225 mg, 1.0 mol) with benzyl carbamate (226
mg, 1.5 mol), tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and
Ir(ppy)2(dtbbpy)PF6 (5.6 mg, 0.005 mol) afforded 3i as white solid (265 mg, 90%). The compound
matched previously reported characterization data.8h 1H NMR (400 MHz, CDCl3) δ 7.62-7.49 (m,
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4H), 7.46-7.36 (m, 5H), 6.89 (bs, 1H), 5.24 (s, 2H). C NMR (100 MHz, CDCl3) δ ppm 152.9,
140.9, 135.6, 128.7, 128.5, 128.4, 126.4, 126.4, 126.3, 125.4, 125.1, 122.7, 118.0, 67.4.
Benzyl (3,5-bis(trifluoromethyl)phenyl)carbamate (3j): Following the general procedure (GP), the
reaction of 1-bromo-3,5-bis(trifluoromethyl)benzene 2j (293 mg, 1.0 mol) with benzyl carbamate
(226 mg, 1.5 mol), tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and
Ir(ppy)2(dtbbpy)PF6 (5.6 mg, 0.005 mol) afforded 3j as white solid (330 mg, 91%). The compound
data was matched with commercially available compound. 1H NMR (400 MHz, CDCl3) δ 7.90 (s,
2H), 7.58 (s, 1H), 7.43-7.37 (m, 5H), 7.03 (bs, 1H), 5.25 (s, 2H). 13C NMR (100 MHz, CDCl3) δ
ppm 152.8, 139.3, 135.3, 132.9, 132.6, 132.3, 131.9, 128.7, 128.7, 128.4, 124.4, 121.7, 118.2,
116.8, 67.7.
Benzyl (6-(dimethylamino)pyridin-3-yl)carbamate (3k): Following the general procedure (GP),
the reaction of 5-bromo-N,N-dimethylpyridin-2-carbamide 2k (201 mg, 1.0 mol) with benzyl
carbamate (226 mg, 1.5 mol), tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05
mol) and Ir(ppy)2(dtbbpy)PF6 (5.6 mg, 0.005 mol) afforded 3k as white solid (203 mg, 75%). The
compound data was matched with commercially available compound. 1H NMR (400 MHz, CDCl3)
δ 7.51-7.30 (m, 6H), 7.30-7.25 (m, 1H), 7.22-7.16 (m, 1H), 6.22 (d, J =8 Hz, 1H), 5.22 (s, 2H),
3.02 (s, 6H). 13C NMR (100 MHz, CDCl3) δ ppm 158.2, 152.9, 149.5, 139.3, 136.0, 128.5, 128.4,
128.2, 128.2, 100.7, 98.7, 66.8, 37.7.
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Benzyl (6-fluoropyridin-3-yl)carbamate (3l): Following the general procedure (GP), the reaction
of 5-bromo-2-fluoropyridine 2l (175 mg, 1.0 mol) with benzyl carbamate (226 mg, 1.5 mol),
tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6
(5.6 mg, 0.005 mol) afforded 3l as white solid (189 mg, 77%). The compound data was matched
with commercially available compound. 1H NMR (400 MHz, CDCl3) δ 8.10 (s, 2H), 7.44-7.35 (m,
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5H), 6.96-6.89 (m, 2H), 5.23 (s, 2H). C NMR (100 MHz, CDCl3) δ ppm 160.8, 158.4, 153.4,
137.3, 135.5, 132.6, 132.5, 132.0, 131.9, 128.7, 128.6, 128.4, 109.7, 109.3, 67.5.
Benzyl (5-cyanopyridin-2-yl)carbamate (3m): Following the general procedure (GP), the reaction
of 6-bromonicotinonitrile 2m (183 mg, 1.0 mol) with benzyl carbamate (226 mg, 1.5 mol),
tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6
(5.6 mg, 0.005 mol) afforded 3m as white solid (187 mg, 74%). The compound data was matched
with commercially available compound. 1H NMR (400 MHz, DMSO-d6) δ 10.95 (bs, 1H), 8.75
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(s 1H), 8.26-8.21 (m, 1H), 8.02-7.98 (m, 1H), 7.48-7.34 (m, 5H), 5.23 (s, 2H). C NMR (100
MHz, DMSO-d6) δ ppm 155.4, 153.6, 152.6, 142.2, 136.5, 128.9, 128.6, 128.5, 117.8, 112.1,
103.1, 66.8.
Benzyl (5-methylpyridin-2-yl)carbamate (3n): Following the general procedure (GP), the reaction
of 2-bromo-5-methylpyridine 2n (172 mg, 1.0 mol) with benzyl carbamate (226 mg, 1.5 mol),
tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6
(5.6 mg, 0.005 mol) afforded 3n as white solid (183 mg, 76%). The compound data was matched
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with commercially available compound. H NMR (400 MHz, DMSO-d6) δ 10.21 (bs, 1H), 8.08
(s, 1H), 7.74 (d, J =8.4 Hz, 1H), 7.58 (d, J =8.4 Hz, 1H), 7.46-7.30 (m, 5H), 5.17 (s, 2H), 2.21 (s,
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3H). C NMR (100 MHz, DMSO-d6) δ ppm 153.9, 150.3, 148.0, 139.0, 137.0, 128.8, 128.4,
128.3, 127.9, 112.3, 66.1, 17.6.
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Benzyl pyrimidin-5-ylcarbamate (3o): Following the general procedure (GP), the reaction of 5-
bromopyrimidine 2o (158 mg, 1.0 mol) with benzyl carbamate (226 mg, 1.5 mol), tetramethyl
guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6 (5.6 mg,
0.005 mol) afforded 3o as white solid (167 mg, 73%). The compound matched previously reported
characterization data.8i 1H NMR (400 MHz, DMSO-d6) δ 9.88 (s, 1H), 8.85-8.83 (m, 3H), 7.47-
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7.32 (m, 5H), 5.22 (s, 2H). C NMR (100 MHz, DMSO-d6) δ ppm 153.8, 152.9, 146.6, 136.5,
135.0, 128.9, 128.7, 66.9.
Benzyl benzo[b]thiophen-5-ylcarbamate (3p): Following the general procedure (GP), the reaction
of 5-bromobenzo[b]thiophene 2p (213 mg, 1.0 mol) with benzyl carbamate (226 mg, 1.5 mol),
tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6
(5.6 mg, 0.005 mol) afforded 3p as white solid (220 mg, 78%). The compound data was matched
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with commercially available compound. H NMR (400 MHz, CDCl3) δ 8.05 (bs, 1H), 7.81 (d, J
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=8.4 Hz, 1H), 7.52-7.36 (m, 6H), 7.32-7.26 (m, 2H), 6.87 (s, 1H), 5.27 (s, 2H). C NMR (100
MHz, CDCl3) δ ppm 153.6, 140.3, 136.1, 134.9, 134.6, 128.6, 128.4, 128.4, 127.6, 123.8, 122.8,
116.8, 113.2, 67.1.
tert-Butyl (3-cyanophenyl)carbamate (4a): Following the general procedure (GP), the reaction of
3-bromobenzonitrile 2a (182 mg, 1.0 mol) with tert-butyl carbamate (175 mg, 1.5 mol),
tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6
(5.6 mg, 0.005 mol) afforded 4a as white solid (196 mg, 90%). The compound matched previously
reported characterization data.8j 1H NMR (400 MHz, CDCl3) δ 7.83 (s, 1H), 7.56-7.50 (m, 1H),
7.43-7.26 (m, 2H), 6.67 (bs, 1H), 1.54 (s, 9H), 13C NMR (100 MHz, CDCl3) δ ppm 147.5, 134.5,
125.0, 121.7, 117.6, 116.6, 113.8, 108.2, 76.7, 23.5.
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tert-Butyl phenylcarbamate (4b): Following the general procedure (GP), the reaction of
bromobenzene 2b (157 mg, 1.0 mol) with tert-butyl carbamate (175 mg, 1.5 mol), tetramethyl
guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6 (5.6 mg,
0.005 mol) afforded 4b as white solid (142 mg, 74%). The compound matched previously reported
characterization data.8k 1H NMR (400 MHz, CDCl3) δ 7.46-7.24 (m, 4H), 7.09-7.01 (m, 1H), 6.54
(bs, 1H), 1.54 (s, 9H). 13C NMR (100 MHz, CDCl3) δ ppm 152.7, 138.3, 128.9, 123.0, 118.5, 80.5,
28.3.
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tert-Butyl m-tolylcarbamate (4c): Following the general procedure (GP), the reaction of 1-bromo-
3-methylbenzene 2c (171 mg, 1.0 mol) with tert-butyl carbamate (175 mg, 1.5 mol), tetramethyl
guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6 (5.6 mg,
0.005 mol) afforded 4c as white solid (163 mg, 79%). The compound matched previously reported
characterization data.8b 1H NMR (400 MHz, CDCl3) δ 7.35-7.25 (m, 1H), 7.24-7.08 (m, 2H), 6.89
(d, J = 7.2 Hz, 1H), 6.49 (bs, 1H), 2.37 (s, 3H), 1.56 (s, 9H). 13C NMR (100 MHz, CDCl3) δ ppm
152.8, 138.9, 138.2, 128.7, 123.8, 119.1, 115.5, 80.4, 28.3, 21.5.
tert-Butyl [1,1'-biphenyl]-3-ylcarbamate (4d): Following the general procedure (GP), the reaction
of 3-bromo-1,1'-biphenyl 2d (233 mg, 1.0 mol) with tert-butyl carbamate (175 mg, 1.5 mol),
tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6
(5.6 mg, 0.005 mol) afforded 4d as white solid (217 mg, 81%). The compound matched previously
reported characterization data.8l 1H NMR (400 MHz, CDCl3) δ 7.68-7.60 (m, 3H), 7.51-7.43 (m,
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2H), 7.41-7.35 (m, 3H), 7.33-7.29 (m, 1H), 6.61 (bs, 1H), 1.58 (s, 9H). C NMR (100 MHz,
CDCl3) δ ppm 152.7, 142.1, 140.8, 138.7, 129.3, 128.7, 127.4, 127.2, 121.9, 117.3, 117.3, 80.6,
28.3.
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tert-Butyl (4-methoxyphenyl)carbamate (4e): Following the general procedure (GP), the reaction
of 1-bromo-4-methoxybenzene 2e (187 mg, 1.0 mol) with tert-butyl carbamate (175 mg, 1.5 mol),
tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6
(5.6 mg, 0.005 mol) afforded 4e as white solid (167 mg, 75%). The compound matched previously
reported characterization data.8k 1H NMR (400 MHz, CDCl3) δ 7.33-7.27 (m, 2H), 6.87 (d, J = 8.8
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Hz, 2H), 6.43 (bs, 1H), 3.81 (s, 3H), 1.55 (s, 9H), C NMR (100 MHz, CDCl3) δ ppm 155.6,
153.1, 131.4, 120.6, 114.1, 80.2, 55.5, 28.3.
tert-butyl (4-cyanophenyl)carbamate (4g): Following the general procedure (GP), the reaction of
4-Bromo benzonitrile 2g (182 mg, 1.0 mol) with tert-butyl carbamate (175 mg, 1.5 mol),
tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6
(5.6 mg, 0.005 mol) afforded 4g as white solid (198 mg, 91%). The compound matched previously
reported characterization data.8m 1H NMR (400 MHz, CDCl3) δ 7.62 (d, J = 8.8 Hz, 2H), 7.52 (d,
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J = 8.8 Hz, 2H), 6.72 (bs, 1H), 1.57 (s, 9H). C NMR (100 MHz, CDCl3) δ ppm 152.0, 142.6,
133.3, 119.1, 118.1, 105.7, 81.7, 28.2.
Methyl 4-((tert-butoxycarbonyl)amino)benzoate (4h): Following the general procedure (GP), the
reaction of methyl 4-bromobenzoate 2h (215 mg, 1.0 mol) with tert-butyl carbamate (175 mg, 1.5
mol), tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and
Ir(ppy)2(dtbbpy)PF6 (5.6 mg, 0.005 mol) afforded 4h as white solid (225 mg, 90%). The
compound matched previously reported characterization data.8n 1H NMR (400 MHz, CDCl3) δ
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8.01 (d, J = 8.8 Hz, 2H), 7.47 (d, J = 8.4 Hz, 2H), 6.71 (bs, 1H), 3.93 (s, 3H), 1.56 (s, 9H). C
NMR (100 MHz, CDCl3) δ ppm 166.7,152.2, 142.7, 130.9, 124.3, 117.3, 81.2, 51.9, 28.2.
tert-Butyl (4-(trifluoromethyl)phenyl)carbamate (4i): Following the general procedure (GP), the
reaction of 1-bromo-4-(trifluoromethyl)benzene 2i (225 mg, 1.0 mol) with tert-butyl carbamate
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(175 mg, 1.5 mol), tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and
Ir(ppy)2(dtbbpy)PF6 (5.6 mg, 0.005 mol) afforded 4i as white solid (232 mg, 89%). The compound
matched previously reported characterization data.8j 1H NMR (400 MHz, CDCl3) δ 7.58 (d, J = 8.4
Hz, 2H), 7.51 (d, J = 8.8 Hz, 2H), 6.71 (bs, 1H), 1.57 (s, 9H). 13C NMR (100 MHz, CDCl3) δ ppm
152.3, 141.5, 128.3, 126.3, 126.3, 126.2, 126.2, 125.6, 125.3, 124.9, 124.6, 124.3, 122.9, 120.2,
117.9, 81.3, 28.2.
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tert-butyl (3,5-bis(trifluoromethyl)phenyl)carbamate (4j): Following the general procedure (GP),
the reaction of 1-bromo-3,5-bis(trifluoromethyl)benzene 2j (293 mg, 1.0 mol) with tert-butyl
carbamate (175 mg, 1.5 mol), tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05
mol) and Ir(ppy)2(dtbbpy)PF6 (5.6 mg, 0.005 mol) afforded 4j as white solid (302 mg, 92%).
The compound matched previously reported characterization data.8o 1H NMR (400 MHz, CDCl3)
δ 7.88 (s, 2H), 7.54 (s, 1H), 6.86 (bs, 1H), 1.55 (s, 9H). 13C NMR (100 MHz, CDCl3) δ ppm 152.1,
139.8, 132.8, 132.4, 132.1, 131.8, 127.2, 124.5, 121.7, 119.0, 117.9, 116.2, 116.2, 116.1, 81.9,
28.1.
tert-butyl (6-fluoropyridin-3-yl)carbamate (4l): Following the general procedure (GP), the
reaction of 5-bromo-2-fluoropyridine 2l (175 mg, 1.0 mol) with tert-butyl carbamate (175 mg, 1.5
mol), tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and
Ir(ppy)2(dtbbpy)PF6 (5.6 mg, 0.005 mol) afforded 4l as white solid (159 mg, 75%). The compound
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data was matched with commercially available compound. H NMR (400 MHz, CDCl3) δ 8.19-
8.01 (m, 2H), 6.95-6.88 (m, 1H), 6.78 (bs, 1H), 1.54 (s, 9H). 13C NMR (100 MHz, CDCl3) δ ppm
160.5, 158.2, 152.7, 137.3, 133.1, 131.8, 109.5, 109.1, 81.4, 28.2.
tert-butyl (5-methylpyridin-2-yl)carbamate (4n): Following the general procedure (GP), the
reaction of 2-bromo-5-methylpyridine 2n (172 mg, 1.0 mol) with tert-butyl carbamate (175 mg,
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1.5 mol), tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and
Ir(ppy)2(dtbbpy)PF6 (5.6 mg, 0.005 mol) afforded 4n as white solid (153 mg, 74%). The
compound matched previously reported characterization data.8p 1H NMR (400 MHz, CDCl3) δ
9.35 (bs, 1H), 8.22 (s, 1H), 7.93 (d, J = 8.4 Hz, 1H), 7.55-7.49 (m, 1H), 2.3 (s, 3H), 1.59 (s, 9H).
13C NMR (100 MHz, CDCl3) δ ppm 152.9, 150.4, 147.4, 138.9, 127.2, 112.0, 80.5, 28.4, 17.6.
tert-Butyl pyrimidin-5-ylcarbamate (4o): Following the general procedure (GP), the reaction of
5-bromopyrimidine 2o (158 mg, 1.0 mol) with tert-butyl carbamate (175 mg, 1.5 mol), tetramethyl
guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6 (5.6 mg,
0.005 mol) afforded 4o as white solid (138 mg, 71%). The compound matched previously
reported characterization data.8q 1H NMR (400 MHz, CDCl3) δ 8.96-8.87 (m, 3H), 7.12 (bs, 1H),
1.56 (s, 9H). 13C NMR (100 MHz, CDCl3) δ ppm 152.9, 152.2, 146.5, 134.0, 82.1, 28.2.
tert-Butyl benzo[b]thiophen-5-ylcarbamate (4p): Following the general procedure (GP), the
reaction of 5-bromobenzo[b]thiophene 2p (213 mg, 1.0 mol) with tert-butyl carbamate (175 mg,
1.5 mol), tetramethyl guanidine (172 mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and
Ir(ppy)2(dtbbpy)PF6 (5.6 mg, 0.005 mol) afforded 4p as white solid (204 mg, 82%). The
compound matched previously reported characterization data.8r 1H NMR (400 MHz, CDCl3) δ
8.05 (s, 1H), 7.79 (d, J = 8.8 Hz, 1H), 7.47 (d, J = 5.6 Hz, 1H), 7.32-7.27 (m, 1H), 7.26-7.21 (m,
1H), 6.64 (bs, 1H), 1.58 (s, 9H). 13C NMR (100 MHz, CDCl3) δ ppm 153.0, 140.3, 135.2, 134.4,
127.4, 123.8, 122.6, 116.7, 112.9, 80.6, 28.4.
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N-(4-cyanophenyl)benzamide (4r): Following the general procedure (GP), the reaction of 4-bromo
benzonitrile 2g (182 mg, 1.0 mol) with benzamide (182 mg, 1.5 mol), tetramethyl guanidine (172
mg, 1.5 mol), NiCl2.glyme (11 mg, 0.05 mol) and Ir(ppy)2(dtbbpy)PF6 (5.6 mg, 0.005 mol)
afforded 4r as white solid (200 mg, 90%). The compound matched previously reported
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characterization data.8s 1H NMR (400 MHz, CDCl3): δ ppm 8.02 (bs, 1H), 7.87 (d, J = 7.2 Hz,
5
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2H), 7.80 (m, 2H), 7.66 (d, J=8.4 Hz, 2H), 7.60 (m, 1H), 7.51 (m, 2H). C NMR (100 MHz,
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CDCl3): δ ppm 166.2, 143.5, 134.4, 133.1, 132.1, 128.5, 127.9, 120.2, 119.1, 105.3.
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Supporting Information Available: Copies of NMR spectra of all the compounds, This material
is available free of charge via the Internet at http://pubs.acs.org.
Dedication
Dedicated to Professor E. J. Corey (Sheldon Emory Professor Emeritus, Harvard University,
USA) on the occasion of his 90th birthday.
Acknowledgment
We thank Mr.Vivek Sharma (Piramal Enterprises Limited) for valuable support.
Conflicts of interest
There are no conflicts to declare.
References
(1)
For selected reviews, see: (a) Staveness, D.; Bosque, I.; Stephenson, C. R. Free Radical
Chemistry Enabled by Visible Light-Induced Electron Transfer. Acc. Chem. Res. 2016, 49,
2295; (b) Chen, J. – R.; Hu, X. –Q.; Lu, L. –Q.; Xiao, W. –J. Exploration of Visible-Light
Photocatalysis in Heterocycle Synthesis and Functionalization: Reaction Design and
Beyond. Acc. Chem. Res. 2016, 49, 1911; (c) Shaw, M. H.; Twilton, J.; MacMillan, D.
W. C. Photoredox Catalysis in Organic Chemistry. J. Org. Chem. 2016, 81, 6898; (d)
Marzo, L.; Pagire, S. R.; Reiser, O.; König, B. Visible-Light Photocatalysis: Does it make
a difference in Organic Synthesis. Angew. Chem. Int. Ed. 2018, 57, 10034. (e) Xie, J.; Jin,
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8
9
H.; Hashmi, A. S. K. The recent achievements of redox-neutral radical C–C cross-coupling
enabled by visible-light. Chem. Soc. Rev., 2017, 46, 5193and references cited therein.
(a) Cano-Yelo, H.; Deronzier, A. Photo-oxidation of some carbinols by the Ru(II)
polypyridyl complex-aryl diazonium salt system. Tetrahedron Lett. 1984, 25, 5517; (b)
Cano-Yelo, H.; Deronzier, A. Photocatalysis of the pschorr reaction by tris-(2,2′-
bipyridyl)ruthenium(II) in the phenanthrene series. J. Chem. Soc., Perkin Trans. 2, 1984,
1093; (c) Cano-Yelo, H.; Deronzier, A. Photocatalysis of the pschorr reaction by
Ru(bpy)32+ J. Photochem. 1987, 37, 315.
(2)
10
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51
52
53
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59
60
(3)
(a) Creutz, S. E.; Lotito, K. J.; Fu, G. C.; Peters, J. C. Photoinduced Ullmann C–N
coupling: demonstrating the viability of a radical pathway. Science 2012, 338, 647; (b)
Kainz, Q. M.; Matier, C. D.; Bartoszewicz, A.; Zultanski, S. L.; Peters, J. C.; Fu, G. C.
Asymmetric copper-catalyzed C-N cross-couplings induced by visible light. Science 2016,
351, 681; (c) Hwang, S. J.; Powers, D. C.; Maher, A. G.; Anderson, B. L.; Hadt, R. G.;
Zheng, S. –L.; Chen, Y.-S.; Nocera, D. G. Trap-Free Halogen Photoelimination from
Mononuclear Ni(III) Complexes. J. Am. Chem. Soc. 2015, 137, 6472; (d) Heitz, D. R.;
Tellis, J. C.; Molander, G. A. Photochemical Nickel-Catalyzed C–H Arylation: Synthetic
Scope and Mechanistic Investigations. J. Am. Chem. Soc. 2016, 138, 12715; (e) Shields,
B. J.; Doyle, A. G. Direct C(sp3)–H Cross Coupling Enabled by Catalytic Generation of
Chlorine Radicals. J. Am. Chem. Soc. 2016, 138, 12719.
(4)
(5)
(6)
Corcoran, E. B.; Pirnot, M. T.; Lin, S.; Dreher, S. D.; DiRocco, D. A.; Davies, I. W.;
Buchwald, S. L.; MacMillan, D. W. C. Aryl amination using ligand-free Ni(II) salts and
photoredox catalysis. Science 2016, 353, 279.
Kim, T.; McCarver, S. J.; Lee, C.; MacMillan, D. W. C. Sulfonamidation of Aryl and
Heteroaryl Halides through Photosensitized Nickel Catalysis. Angew. Chem. Int. Ed. 2018,
57, 3488.
(a) Hartwig, J. F. Approaches to catalyst discovery. New carbon–heteroatom and
carbon–carbon bond formation. Pure Appl. Chem. 1999, 71, 1417; (b) Surry, D. S.;
Buchwald, S. L. Biaryl Phosphane Ligands in Palladium‐Catalyzed Amination. Angew.
Chem., Int. Ed. 2008, 47, 6338; (c) Wolfe, J. P.; Wagaw, S.; Marcoux, J. –F.; Buchwald,
S. L. Rational Development of Practical Catalysts for Aromatic Carbon−Nitrogen Bond
Formation. Acc. Chem. Res. 1998, 31, 805; (d) Hartwig, J. F. Carbon−Heteroatom Bond-
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5
6
7
8
9
Forming Reductive Eliminations of Amines, Ethers, and Sulfides. Acc. Chem. Res. 1998,
31, 852.
(7)
(a) Nielsen, M. K.; Shields, B. J.; Liu, J.; Williams, M. J.; Zacuto, M. J.; Doyle, A. G.
Mild, Redox-Neutral Formylation of Aryl Chlorides through the Photocatalytic Generation
of Chlorine Radicals. Angew. Chem. Int. Ed. 2017, 56, 7191; (b) Zhang, P.; Le, C. C.;
MacMillan, D. W. C. Silyl Radical Activation of Alkyl Halides in Metallaphotoredox
Catalysis: A Unique Pathway for Cross-Electrophile Coupling. J. Am. Chem. Soc. 2016,
138, 8084; (c) Wang, H.; Zhang, D.; Bolm, C. Sulfoximidations of Benzylic C−H bonds
by Photocatalysis. Angew. Chem. Int. Ed. 2018, 57, 5863.
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52
53
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55
56
57
58
59
60
(8)
(a) Manabu, H.; Sho, K.; Katsuhiko, M.; Kazuaki I. Complementary Regioselectivity
in the Cu(I)-Catalyzed Diamination of Conjugated Dienes To Form Cyclic Sulfamides
Org. Lett. 2011, 13, 430. (b) Christophe, S.; Patrick, W.; Maud, B.; Frederic, B.; Jean-
Jacques, B.; Martin, S. Buchwald–Hartwig reactions in water using surfactants
Tetrahedron, 2014, 70, 3413. (c) Diana, C; Emma. L. D.; Dima, S.; Louise C. Y.; Pritchard,
J. M.; Macdonald, Simon J. F.; Budd, D. C.; Jamieson, C.; Watson, Allan J. B.;
Identification of a novel class of autotaxin inhibitors through cross-screening Med. Chem.
Commun. 2015, 6, 1149. (d) Sabesan, Y.; Scott, J. M.; N-Methylimidazole-catalyzed
Synthesis of Carbamates from Hydroxamic Acids via the Lossen Rearrangement Org. Lett.
2013, 15, 602. (e) Moon, Soo-Yeon; Kim, U. Bin; Sung, Dan-Bi; Kim, Won-Suk; A
Synthetic Approach to N-Aryl Carbamates via Copper-Catalyzed Chan–Lam Coupling at
Room Temperature J. Org. Chem. 2015, 80, 1856. (f) Stephen D. S.; Joakim, A.; Kodis,
G.; Moore, A. L.; Moore, T. A..; Gust, D.; Photochromic Control of Photoinduced Electron
Transfer. Molecular Double-Throw Switch J. Am. Chem. Soc. 2005, 127, 2717. (g) Wipf,
P.; Maciejewski, J. P.; Titanocene(III)-Catalyzed Formation of Indolines and Azaindolines
Org. Lett. 2008, 10, 4383. (h) Chen, Li.; Qingmin, W.; Huang, R.; Mao, C.; Shang, J.;
Fuchun, Bi. Synthesis and Insecticidal Evaluation of Propesticides of Benzoylphenylureas
J. Agricultural and Food Chemistry, 2005, 53, 38. (i) Nicholas, A. I.; Dobarco, S.;
Lipshutz, B. H.; Installation of protected ammonia equivalents onto aromatic &
heteroaromatic rings in water enabled by micellar catalysis Green Chemistry, 2014, 16,
1480. (j) Vinogradova, E. V.; Park, N. H.; Fors, B. P.; Buchwald, Stephen L. Palladium-
Catalyzed Synthesis of N-Aryl Carbamates Org. Lett. 2013, 15, 1394. (k) Fangfang, Ma.;
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Xiaomin, X.; Lei, Z.; Zhiyong, P.; Ding, L.; Lei, Hu; Zhaoguo, Z. Palladium-Catalyzed
Amidation of Aryl Halides Using 2-Dialkylphosphino-2′-alkoxyl-1,1′-binaphthyl as
Ligands J. Org. Chem. 2012, 77, 5279. (l) Matthias, S; Alain, Z.; Christian, J. L. A
fluorescence-quencher pair for DNA hybridization studies based on hydrophobic base
surrogates Tetrahedron, 2007, 63, 3440. (m) Shen, T.; Teng, W.; Chong, Q., Ning, J.;
Silver‐Catalyzed Nitrogenation of Alkynes: A Direct Approach to Nitriles through C-C
Bond Cleavage Angew. Chem, Int. Ed, 2013, 52, 6677. (n) Xiong, X.; Yeung, YY.; Highly
ortho-Selective Chlorination of Anilines Using a Secondary Ammonium Salt
Organocatalyst Angew. Chem, Int. Ed, 2016, 55, 16101. (o) Cheng, G.; Wang, P.; Yu, JQ.;
meta-C-H Arylation and Alkylation of Benzylsulfonamide Enabled by a
Palladium(II)/Isoquinoline Catalyst Angew. Chem, Int. Ed, 2017, 56, 8183. (p) Suren, H.;
Rade, M.; Milos, P.; Veselin, N.; Vladimir, S.; A Base Promoted Cyclization of N-
Propargylaminopyridines. Synthesis of Imidazo[1,2-a]pyridine Derivatives Org. Lett.
2011, 13, 2286. (q) Patrick, W.; Maud, B.; Christelle, D.; Frederic, B.; Jean-Jacques, B.;
Christophe, S.; Martine, S.; t-BuXPhos: a highly efficient ligand for Buchwald–Hartwig
coupling in water Green Chemistry, 2014, 16, 4170. (r) Serena, F.; Johannes, W.;
Michelangelo, S.; Ligandless Copper‐Catalyzed Coupling of Heteroaryl Bromides with
Gaseous Ammonia Adv. Synth. Catal., 2013, 355, 627. (s) Wenyou, F.; Youqing, Y.;
Jianhua, L.; Qijian, J.; Wang, Z. Copper-Catalyzed N-Benzoylation of Amines via Aerobic
C–C Bond Cleavage J. Org. Chem. 2015, 80, 8782.
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