Ir-Catalyzed C?H Amidation of Aldehydes with Stoichiometric/Catalytic Directing Group

Article abstract of DOI:10.1002/chem.201603805

Ir-catalyzed sp²C?H amidation of aldehydes with various anilines as stoichiometric or catalytic directing groups was accomplished. A wide range of substrates were selectively amidated in good to excellent yields with broad functional group tolerance. The iridacycle complexes were isolated, characterized, and proved as key intermediates. Kinetic studies and Hammett plots provided detailed understandings of this amidation. According to the mechanism, the electron-rich ArSO₂N₃was proved effective for intermolecular sp³C?H amidation.

Full text of DOI:10.1002/chem.201603805

DOI: 10.1002/chem.201603805
Full Paper
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Organic Chemistry
Ir-Catalyzed CÀH Amidation of Aldehydes with Stoichiometric/
Catalytic Directing Group
Yun-Fei Zhang,[a] Bin Wu,[a] and Zhang-Jie Shi*[a, b]
Abstract: Ir-catalyzed sp2 CÀH amidation of aldehydes with
various anilines as stoichiometric or catalytic directing
groups was accomplished. A wide range of substrates were
selectively amidated in good to excellent yields with broad
functional group tolerance. The iridacycle complexes were
isolated, characterized, and proved as key intermediates. Ki-
netic studies and Hammett plots provided detailed under-
standings of this amidation. According to the mechanism,
the electron-rich ArSO2N3 was proved effective for intermo-
lecular sp3 CÀH amidation.
scopes.[7c] To date, CÀC and CÀO formation were successfully
resolved with different nucleophiles.[7] Due to step- and atom-
economy, much attention has recently been paid to transition-
metal-catalyzed CÀH amination/amidation.[8] Indeed, both nu-
cleophilic and electrophilic aminating/amidating reagents have
been applied.[9] Recently, Chang,[10] Jiao,[11] Bolm[12] and
others[13] made significant contributions in transition-metal-cat-
alyzed CÀH amidation using organic azides as amidating re-
agents. Herein we report the successful iridium-catalyzed inter-
molecular CÀH amidation of aldehydes through stoichiometric
and catalytic directing strategy (Scheme 1).
Introduction
Transition-metal-catalyzed CÀH activation with directing strat-
egy is one of the most reliable pathways to form CÀC and CÀX
bonds (X=heteroatom) with both efficiency and selectivity.[1]
Due to the easy preparation and simple removal ability, the
imine derivative is considered as an ideal directing group of al-
dehydes/ketones for direct CÀH functionalization.[2] Compared
to the prepared directing group in substrates, using a catalytic
amount of amine as transient directing group for aldehydes/
ketones is much more desirable. An early example was report-
ed by Jun and co-workers using 2-amino pyridine as a transient
directing group for Rh-catalyzed activation of aldehydic CÀH
bonds.[3] Dong and co-workers used an enamine intermediate
with a pyridine moiety as a transient directing group to realize
a-CÀH functionalization of ketone.[4] Seayad and co-workers
used 4-trifluoromethylaniline as transient directing group to re-
alize the oxidative coupling of aldehydes.[5] Very recently, Yu
and co-workers reported another successful example on direct
functionalization of C(sp3)ÀH bonds using amino acid as a tran-
sient directing group.[6] Considering the importance of such
processes, it is still highly appealing to develop new transfor-
mations based on this strategy.
Scheme 1. Direct CÀH amidation of aldehyde through stoichiometric and
catalytic directing strategy.
Results and Discussion
Aldehydes are readily available and easily transformable.
Due to the weak coordinating ability and instability of the pro-
duced intermediates, direct b-CÀH functionalization of alde-
hydes is far behind, with limited reaction classes and substrate
We initially tried the desirable ortho-amidation of 2-bromoben-
zaldehyde with TsN3 in the presence of [Cp*IrCl2]2 (5 mol%)
and AgPF6 (20 mol%) as catalyst [Eq. (1)]. No reaction occurred
as expected. To our delight, when using the imine 1a as sub-
strate, CÀH amidation took place smoothly and the amidated
aldehyde 3a was isolated in 91% yield after a simple workup,
indicating the vital role of iminyl group. After the systematic
optimization we found that both the catalyst loading and the
amount of TsN3 could be reduced and the desired aldehyde
was obtained in a 92% yield [Eq. (2), method A; for details, see
the Supporting Information]. Based on this result, we envis-
aged that the presence of catalytic amounts of proper amines
might also enhance the reactivity mediated by imine. Indeed,
the results indicated that, by using a catalytic amount of 3-tri-
fluomethylaniline, the desired product was obtained in 84%
[a] Y.-F. Zhang, B. Wu, Prof. Dr. Z.-J. Shi
Beijing National Laboratory of Molecular Sciences (BNLMS) and
Key Laboratory of Bioorganic Chemistry and Molecular Engineering of
Ministry of Education, College of Chemistry and
Molecular Engineering and Green Chemistry Center
Peking University, Beijing, 100871 (P.R. China)
E-mail: zshi@pku.edu.cn
[b] Prof. Dr. Z.-J. Shi
State Key Laboratory of Organometallic Chemistry
Chinese Academy of Sciences, Shanghai, 200032 (P. R. China)
Supporting information for this article is available on the WWW under
http://dx.doi.org/10.1002/chem.201603805.
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isolated yield [Eq. (3), method B; for details, see the Supporting
Information).
Table 1. Iridium-catalyzed sp2 amidation of aldehydes or imines 1 with
organic azides 2.[a]
With the optimal conditions in hand, a variety of imines and
organic azides were tested based on methods A and B and
representative data are shown in Table 1. Generally, the yields
with catalytic amount of aniline derivatives gave good to ac-
ceptable yields, albeit lower than those from the correspond-
ing imines. Different halo-substituents, including Br (3a), Cl
(3b) ad I (3c) survived well and comparable efficacy was ob-
tained. While F (3d) was present, a relatively lower yield was
obtained. Other functional groups, such as nitro- (3e), trifluoro-
methyl- (3 f), and methyl- (3g), equipped at the ortho position,
also gave good results. However, the ester group (3h) at the
ortho position gave much lower efficiency while ortho-cyano-
(3i) and methoxy- (3j) substituents terminated the reaction;
this probably arises from the chelating effect of heteroatoms
of substituents and iminyl groups to cationic Ir-complexes to
prevent CÀH activation. The meta substituents were also
tested and we found that 3-I (3k) gave a good yield while 3-
NO2 (3l) gave lower efficiency.
[a] Conditions: yields based on method B are shown outside of parenthe-
ses; yields based on method A are shown in parentheses. PMP=4-me-
thoxylphenyl. [b] [Cp*IrCl2]2 (4 mol%) and AgPF6 (24 mol%). [c] [Cp*IrCl2]2
(5 mol%), AgPF6 (20 mol%) and TsN3 (2.0 equiv). [d] 1208C. [e] [Cp*IrCl2]2
(5 mol%) and AgPF6 (20 mol%).
Disubstituted imines containing different functional groups
also reacted well. Dihalo-substituted imines showed great reac-
tivity to produce the multisubstituted products (3m–3o) and
the methyl substituted 3p was also workable. Interestingly, the
1-naphthaldehyde derivative 3q gave a credible reactivity
while the 2-naphthaldehyde 3r completely failed. N-Phenyl
benzaldimine 1s was also suitable and both mono- and diami-
dated products were obtained in good yield in the presence of
5 mol% of Ir catalyst (3s). This result also indicates that the
amide substituent is compatible for the additional amidation.
We further examined the scope of organic azides (Table 1). A
variety of functional groups, such as methoxy (4a), chloro (4c),
fluoro (4d), acetyl (4e), trifluoromethyl (4 f), nitro (4g) and
bromo (4h) moieties, were compatible. Probably owing to
steric effects, the 2-Br substituted substrate 4i only gave
a modest yield at a higher temperature with a higher catalyst
loading. At this stage, acyl azides, phosphoryl azides and aryl
azides were not applicable (see the Supporting Information).
Moreover, the directing ability of imines with different sub-
stituents of aryl group was investigated and the results are
shown in Scheme 2. Probably due to the competitive coordina-
Scheme 2. Comparison of the directing ability of imines with different sub-
stituents.
tion with the iridium catalyst center, NMe2 substituted imine
gave a very poor yield. Imines bearing other substituents gave
good results while showing an obvious electronic effect.
To obtain mechanistic insights into this amidation, a series
of experiments were conducted.[14] First, a remarkable H/D ex-
change of 19% in the product was found upon addition of
D2O, thereby implying CÀH activation was reversible under this
condition. Further, an intermolecular kinetic isotope effect (KIE)
of kH/kD =1.05, indicates that the CÀH cleavage is not involved
in the turnover-limiting step of the catalytic cycle (Scheme 3).
We further synthesized the iridacycle A and cationic species B
according to reported methods.[15] B was fully characterized by
1H NMR spectroscopy and ESI-HRMS. To further confirm the
structure of B, the complex B’ was prepared through ligand ex-
change with pyridine from B. The structure was confirmed by
its single-crystal X-ray diffraction. The successful conversion of
iridacycle B to 3n indicated the crucial role of AgPF6 to gener-
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ate activated species since neutral complex A completely
failed. The iridacycle B also successfully catalyzed the CÀH ami-
dation albeit at a lower efficiency (Scheme 4). Compared to
standard condition, lower efficiency might imply that B was
probably the resting state of catalyst.
Scheme 3. Deuterium-labeling experiments.
Scheme 4. Experimental analysis of iridacycles. PMP=4-methoxyphenyl.
To understand the kinetic behavior of the reactants and cat-
alyst in this catalytic cycle, the kinetic characterization of this
amidation was then surveyed. To simplify the transformation,
the reaction was carried out with imine 1n and azide 2a in
the presence of cationic iridacycle B as catalyst (see the Sup-
porting Information). A plot of kobs versus imine 1n clearly
showed an inverse first-order dependence (Figure 1a), howev-
er, the plot of kobs versus azide 2a (Figure 1b) and catalyst B
(Figure 1c) clearly showed a first-order dependence. These re-
sults suggest that the formation of a CÀN bond was probably
involved in the rate-limiting step.[16]
Figure 1. a) Plot of initial rate versus 1/imine 1n. b) Plot of initial rate versus
TsN3 2a. c) Plot of initial rate versus catalyst B.
Since most sulfonyl azide and aryl amines showed credible
while diverse reactivity (Table 1 and Scheme 2), we further con-
ducted the Hammett plots to support our conclusion. The
effect of different substituents of arenesulfonyl azides on the
reactivity of amidation was investigated. The initial competitive
experiments of different electronic arenesulfonyl azides indicat-
ed that the effect on the reactivity of the substituent followed
the sequence: OMe>H>CF3 (Scheme 5).
OMe, CH3, H, Cl, CF3, NO2) were tested and Hammett plots
were prepared (Figure 2a and b). Both 1 values of À0.640 and
À1.396 were obtained. These results clearly demonstrate that
electron-donating substituents at the para-position of the
imines and arenesulfonyl azides had an accelerating effect on
the rate of reaction, which probably arises from the better co-
ordinating ability toward the Ir center.
Based on these results, the relative rates of imines and are-
nesulfonyl azides bearing different electronic substituents (R=
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Scheme 5. Intermolecular competitive experiment of different arenesulfonyl
azides.
Scheme 6. Proposed mechanism for iridium-catalyzed amidation of imine
1n.
Compared to intermolecular sp2 CÀH amidation, intermolec-
ular amidation at unreactive sp3 CÀH bonds still remains
a great challenges.[17] Moreover, catalytic b-functionalization of
aliphatic aldehyde or ketone directed by imines is far behind.[6]
Encouraged by the efficient sp2 CÀN formation, we intended
to expand such an amidation to the sp3 CÀH bond. However,
we found that the frequently used TsN3 shows a very low effi-
ciency. According to the Hammett plot, electron-donating are-
nesulfonyl azide should be promising. Indeed, the b-amidation
of aliphatic aldehydes was achieved, albeit in a moderate
yield at this stage (Scheme 7). Further optimization of this syn-
thetic methodology is underway.
Figure 2. a) Hammett plot of different imines. b) Hammett plot of different
arenesulfonyl azides.
Scheme 7. Iridium-catalyzed sp3 CÀH amidation of imine with azide.
Based on the results and previous reports,[10–13,16c] the mech-
anism is proposed in Scheme 6. Initially, an active cationic
Cp*Ir+ species from [Cp*IrCl2]2 is produced with AgPF6, which
facilitates CÀH activation to generate the five-membered irida-
cycle C. The coordination of C with organic azide leads to D.
Subsequent extrusion of one molecular N2 generates E. Inser-
tion of an amido moiety to E generates the six-membered iri-
dacyclic species F, followed by protonation to deliver the ami-
dated product and to regenerate the catalyst to facilitate the
catalytic cycle. Notably, C was a possible resting state, which
was characterized by ESI-HRMS. Intermediate B was one syn-
thetic pseudo-resting state stabilized by the ligand. Fortunate-
ly, intermediate F was also confirmed by HRMS.
Conclusions
In conclusion, we demonstrate a successful example of Ir-cata-
lyzed sp2 CÀH amidation of aldehydes with amine as stoichio-
metric and catalytic directing group. This chemistry showed
broad functional group tolerance. Cycloiridation complexes as
key intermediates were characterized by X-ray crystallography
and other analytical methods. Kinetic study of the reactants
and catalyst in a catalytic cycle were also conducted and led to
the conclusion that the formation of the CÀN bond was in-
volved in the turnover-limiting step through an inner sphere
pathway. Hammett plot of both imines and arenesulfonyl
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Chem. Soc. 2004, 126, 2300; c) P.-S. Lee, T. Fujita, N. Yoshikai, J. Am.
Chem. Soc. 2011, 133, 17283; d) D. N. Tran, N. Cramer, Angew. Chem. Int.
Ed. 2011, 50, 11098; Angew. Chem. 2011, 123, 11294; e) M. J. Tredwell,
M. Gulias, N. Gaunt Bremeyer, C. C. C. Johansson, B. S. L. Collins, M. J.
Gaunt, Angew. Chem. Int. Ed. 2011, 50, 1076; Angew. Chem. 2011, 123,
1108; f) G. Choi, H. Tsurugi, K. Mashima, J. Am. Chem. Soc. 2013, 135,
13149; g) R. Bisht, B. Chattopadhyay, J. Am. Chem. Soc. 2016, 138, 84.
[3] C.-H. Jun, H. Lee, J.-B. Hong, J. Org. Chem. 1997, 62, 1200.
[4] a) Z. Wang, B. J. Reinus, G. Dong, J. Am. Chem. Soc. 2012, 134, 13954;
b) F. Mo, G. Dong, Science 2014, 345, 68.
[5] P. W. Tan, N. A. B. Juwaini, J. Seayad, Org. Lett. 2013, 15, 5166.
[6] F.-L. Zhang, K. Hong, T.-J. Li, H. Park, J.-Q. Yu, Science 2016, 351, 252.
[7] a) N. Gꢂrbꢂz, I. ꢃzdemir, B. C¸etinkaya, Tetrahedron Lett. 2005, 46, 2273;
b) K. Padala, M. Jeganmohan, Org. Lett. 2012, 14, 1134; c) F. Yang, K.
Rauch, K. Kettelhoit, L. Ackermann, Angew. Chem. Int. Ed. 2014, 53,
11285; Angew. Chem. 2014, 126, 11467; d) X. Liu, X. Li, H. Liu, Q. Guo, J.
Lan, R. Wang, J. You, Org. Lett. 2015, 17, 2936; e) R. Santhoshkumar, S.
Mannathan, C.-H. Cheng, J. Am. Chem. Soc. 2015, 137, 16116.
[8] For selected examples, see: a) K.-H. Ng, A. S. C. Chan, W.-Y. Yu, J. Am.
Chem. Soc. 2010, 132, 12862; b) C. Grohmann, H. Wang, F. Glorius, Org.
Lett. 2012, 14, 656; c) G. He, Y. Zhao, S. Zhang, C. Lu, G. Chen, J. Am.
Chem. Soc. 2012, 134, 3; d) Q. Zhang, K. Chen, W. Rao, Y. Zhang, F.-J.
Chen, B.-F. Shi, Angew. Chem. Int. Ed. 2013, 52, 13588; Angew. Chem.
2013, 125, 13833; e) T. Matsubara, S. Asako, L. Ilies, E. Nakamura, J. Am.
Chem. Soc. 2014, 136, 646.
azides provided further evidence to support the catalytic cycle.
Moreover, Ir-catalyzed sp3 CÀH amidation directed by imine
was developed based on the understanding of the mechanism.
Further efforts to expand this chemistry are under way.
Experimental Section
General procedure for iridium-catalyzed sp2 amidation of
imine 1a
To
a 50 mL reaction tube (sealed tube), [CpIrCl2]2 (3.2 mg,
0.004 mmol) and the imine 1a (58.0 mg, 0.2 mmol) were added
under air atmosphere. AgPF6 (6.0 mg, 0.024 mmol) was added in
a glovebox. TsN3 (42 mL, 0.24 mmol) was added and DCE (1,2-di-
chloorethane, 2.0 mL) was injected into the system. The tube was
sealed and connected to a Wattecs parallel reactor at 1008C for
12 h. After cooling to room temperature, the solution was removed
to a 50 mL flask with 10 mL of THF, 5 mL of hydrochloric acid (2m)
was added, the mixture was stirred at RT for 1 h, and extracted
with DCM (3ꢁ15 mL). The combined organic phase was dried over
anhydrous Na2SO4, concentrated and crude product was purified
by flash chromatography on silica gel with petroleum ether/EtOAc
(10:1 to 5:1) as an eluent to give the product (65.2 mg, 92%).
[9] For selected reviews: a) J. L. Jeffrey, R. Sarpong, Chem. Sci. 2013, 4,
4092; b) M.-L. Louillat, F. W. Patureau, Chem. Soc. Rev. 2014, 43, 901;
c) O. V. Zatolochnaya, V. Gevorgyan, Nat. Chem. 2014, 6, 661.
General procedure for iridium-trifluomethylaniline catalyzed
sp2 amidation of 2-bromobenzaldehyde
[10] For selected examples, see: a) J. Y. Kim, S. H. Park, J. Ryu, S. H. Cho, S. H.
Kim, S. Chang, J. Am. Chem. Soc. 2012, 134, 9110; b) J. Ryu, K. Shin, S. H.
Park, J. Y. Kim, S. Chang, Angew. Chem. Int. Ed. 2012, 51, 9904; Angew.
Chem. 2012, 124, 10042; c) For a selective review, see: K. Shin, H. Kim, S.
Chang, Acc. Chem. Res. 2015, 48, 1040.
[11] Q.-Z. Zheng, Y.-F. Liang, C. Qin, N. Jiao, Chem. Commun. 2013, 49, 5654.
[12] a) P. Becker, R. Pirwerdjan, C. Bolm, Angew. Chem. Int. Ed. 2015, 54,
15493; Angew. Chem. 2015, 127, 15713; b) N. Hermann, P. Becker, C.
Bolm, Angew. Chem. Int. Ed. 2016, 55, 3781; Angew. Chem. 2016, 128,
3845.
[13] For selected examples, see: a) C. Pan, N. Jin, H. Zhang, J. Han, C. Zhu, J.
Org. Chem. 2014, 79, 9427; b) T. Ryu, J. Min, W. Choi, W. H. Jeon, P. H.
Lee, Org. Lett. 2014, 16, 2810; c) H. Wang, Y. Yu, X. Hong, Q. Tan, B. Xu,
J. Org. Chem. 2014, 79, 3279; d) C. Pi, X. Cui, Y. Wu, J. Org. Chem. 2015,
80, 7333; e) M. A. Ali, X. Yao, G. Li, H. Lu, Org. Lett. 2016, 18, 1386; f) T.
Zhang, Z. Wang, X. Hu, M. Yu, T. Deng, G. Li, H. Lu, J. Org. Chem. 2016,
81, 4898.
[14] To simplify the process, including mechanistic studies, kinetic and Ham-
mett plot study, imines were investigated instead of aldehydes.
[15] a) L. Li, W. W. Brennessel, W. D. Jones, J. Am. Chem. Soc. 2008, 130,
12414; b) Y.-K. Sau, X.-Y. Yi, K.-W. Chan, C.-S. Lai, I. D. Williams, W.-H.
Leung, J. Organomet. Chem. 2010, 695, 1399.
To
a 50 mL reaction tube (sealed tube), [CpIrCl2]2 (3.2 mg,
0.004 mmol) and 2-bromobenzaldehyde (37.0 mg, 0.2 mmol) were
added under air atmosphere. AgPF6 (6.0 mg, 0.024 mmol) was
added in a glovebox. Then TsN3 (70 mL, 0.40 mmol), 3-trifluomethy-
laniline (10 mL, 0.08 mmol) were added and DCE (1,2-dichloro-
ethane, 2.0 mL) was injected into the system. The tube was sealed
and connected to a Wattecs parallel reactor at 1008C for 24 h.
After cooling to room temperature, the solution was removed to
a 50 mL flask with 10 mL of THF, 5 mL of hydrochloric acid (2m)
was added, the mixture was stirred at RT for 3 h, and extracted
with DCM (3ꢁ15 mL). The combined organic phase was dried over
anhydrous Na2SO4, concentrated and crude product was purified
by flash chromatography on silica gel with petroleum ether/EtOAc
(10:1 to 5:1) as an eluent to give the product (59.5 mg, 84%).
Acknowledgements
[16] a) M. E. Tauchert, C. D. Incarvito, A. L. Rheingold, R. G. Bergman, J. A.
Ellman, J. Am. Chem. Soc. 2012, 134, 1482; b) Y. Li, X.-S. Zhang, H. Li, W.-
H. Wang, K. Chen, B.-J. Li, Z.-J. Shi, Chem. Sci. 2012, 3, 1634; c) S. H.
Park, J. Kwak, K. Shin, J. Ryu, Y. Park, S. Chang, J. Am. Chem. Soc. 2014,
136, 2492.
Support of this work by the “973” Project from the MOST of
China (2015CB856600, 2013CB228102) and NSFC (No.
21332001) is gratefully acknowledged.
[17] a) H.-Y. Thu, W.-Y. Yu, C.-M. Che, J. Am. Chem. Soc. 2006, 128, 9048; b) J.
Pan, M.-J. Su, S. L. Buchwald, Angew. Chem. Int. Ed. 2011, 50, 8647;
Angew. Chem. 2011, 123, 8806; c) ꢄ. Iglesias, R. ꢄlvarez, ꢄ. R. de Lera, K.
MuÇiz, Angew. Chem. Int. Ed. 2012, 51, 2225; Angew. Chem. 2012, 124,
2268; d) T. Kang, Y. Kim, D. Lee, Z. Wang, S. Chang, J. Am. Chem. Soc.
2014, 136, 4141; e) J. He, T. Shigenari, J.-Q. Yu, Angew. Chem. Int. Ed.
2015, 54, 6545; Angew. Chem. 2015, 127, 6645; f) Q. Gou, G. Liu, Z.-N.
Liu, J. Qin, Chem. Eur. J. 2015, 21, 15491; g) X. Wu, K. Yang, Y. Zhao, H.
Sun, G. Li, H. Ge, Nat. Commun. 2015, 6, 6462.
Keywords: aldehydes · CÀH amidation · imines · iridium ·
transient directing group
[1] For recent reviews, see: a) D. A. Colby, R. G. Bergman, J. A. Ellman,
Chem. Rev. 2009, 109, 624; b) R. Giri, B.-F. Shi, K. M. Engle, N. Maugel, J.-
Q. Yu, Chem. Soc. Rev. 2009, 38, 3242; c) C. S. Yeung, V. M. Dong, Chem.
Rev. 2011, 111, 1215; d) J. L. Roizen, M. E. Harvey, J. Du Bois, Acc. Chem.
Res. 2012, 45, 911; e) G. Rouquet, N. Chatani, Angew. Chem. Int. Ed.
2013, 52, 11726; Angew. Chem. 2013, 125, 11942; f) L. Ackermann, Acc.
Chem. Res. 2014, 47, 281; g) A. Ros, R, Fernandez, ; J. M. Lassaletta,
Chem. Soc. Rev. 2014, 43, 3229.
Received: August 9, 2016
[2] For selected examples, see: a) N. A. Williams, Y. Uchimaru, M. Tanaka,
Dalton Trans. 2003, 236; b) A. R. Dick, K. L. Hull, M. S. Sanford, J. Am.
Published online on && &&, 0000
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FULL PAPER
&
Organic Chemistry
Y.-F. Zhang, B. Wu, Z.-J. Shi*
&& – &&
Ir-Catalyzed CÀH Amidation of
Aldehydes with Stoichiometric/
Catalytic Directing Group
Cat power: Ir-catalyzed CÀH amidation
of aldehydes with various anilines as
stoichiometric or catalytic directing
groups was accomplished (see scheme).
A wide range of substrates were selec-
tively amidated in good to excellent
yields with broad functional group tol-
erance. The iridacycle complexes were
isolated, characterized, and proved as
key intermediates. Kinetic studies and
Hammett plots provided detailed under-
standings of this amidation.
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