4
Tetrahedron
We thank the National Natural Science Foundation of China
Nos. 21102104, 21502065), the Natural Science Foundation of
(
Zhejiang Province (Nos. LY14B020011, LR15B020002) for their
financial support.
References and notes
(
1) (a) Zafar, M.; Zahra, S.; Tahir, M; Mughal, E.; Nazar, M.;
Rafique, H. Turk. J. Chem. 2018, 42, 63. (b) Pontes da Costa,
A; Nunes, D. R.; Tharaud, M.; Oble, J.; Poli, G.; Rieger, J.;
ChemCatChem. 2017, 9, 2167. (c) Wang, G. Z.; Shang, R.;
Cheng, W. M.; Fu, Y. J. Am. Chem. Soc. 2017, 139, 18307. [d]
Miri, S. S.; Khoobi, M.; Ashouri, F.; Jafarpour, F.; Rashidi, R.
P.; Shafiee, A. T. Turk. J. Chem. 2015, 39, 1232. (e) Hajipour,
A. R.; Khorsandi, Z.; Karimi, H.; Appl. Organometal. Chem.
Scheme 3. Control experiments
To explore the mechanism of the oxidative Heck reaction, we
2
015, 29, 805.
carried out several control experiments (scheme 3). Firstly, the
reaction of benzamide (1a) with branched allylic ester (2h)
conducted smoothly to give olefination product (3r) in 30%
yield, which implied that the reaction through a β-OAc
elimination pathway. Secondly, we synthesized terminal alkenyl
product 3ka from literature [12], then treatment of it to the
reaction under standard conditions, 95% yield of product 3l was
isolated. The result indicated that the oxidative Heck reaction
might be involved a proton shift process.
(
2) (a) Jia, C. G.; Piao, D. G.; Oyamada, J.; Lu, W. J.; Kitamura,
T.; Fujiwara, Y. Science. 2000, 287, 1992. (b) Jia, C. G.;
Kitamura, T.; Fujiwara, Y. Acc. Chem. Res. 2001, 34, 633.
(
(
(
3) Fujiwara, Y.; Moritani, I.; Matsuda, M. Tetrahedron. 1968, 24,
4
819.
4) Rakshit, S.; Grohmann, C.; Besset, T.; Glorius, F. J. Am.
Chem. Soc. 2011, 133, 2350.
5) Korkis, S. E.; Burns, D. J.; Lam. H. W. J. Am. Chem. Soc.
2016, 138, 12252.
(
(
6) Feng, C.; Feng, D.; Loh, T. P. Org. Lett. 2013, 15, 3670.
7) (a) Park, J.; Han, S.; Jeon, M.; Mishra, N. K.; Lee, S. Y.; Lee, J.
S.; Kwak, J. H.; Um, S. H.; Kim, I. S. J. Org. Chem. 2016, 81,
Based on aforementioned results [12], as well as our primary
outcomes, a possible mechanism for the oxidative Heck reaction
was proposed as outlined in scheme 4. Initially, [RhCp*Cl
2 2
]
1
1353. (b) Kim, M.; Sharma, S.; Mishra, N. K.; Han, S.; Park,
combine with AgSbF and L1 to form active Rh species, which
6
J.; Kim, M.; Shin, Y.; Kwak, J. H.; Han, S. H.; Kim, I. S. Chem.
Commun., 2014, 50, 11303-11306.
reacted with 1a to produce intermediate A [9, 13]. After
coordination and migratory insertion of allylic ester 2a to form a
seven-membered allylrhodium (III) intermediate B, which
coordinating with carbonate oxygen and metal [8a, 9]. With the
(8) Dai, H. M.; Yu, C.; Wang, Z. H.; Yan, H.; Lu, C. S. Org. Lett.
2016, 18, 3410. Prakash, S.; Muralirajan, K.; Cheng, C. H.
Chem. Commun., 2015, 51, 13362.
assistance of FeF
3
,
intermediate
B
through
a
β-oxygen
(9) (a) Liu, C. W.; Meng, G. R.; Szostak, M. J. Org. Chem. 2016,
8
7
1, 12023. (b) Meng, G. R.; Szostak, M. Org. Lett. 2016, 18,
96. (c) Meng, G. R.; Szostak, M. ACS Catal. 2017, 7, 7251. (d)
elimination process led to alkenyl product C and regenerate
active Rh species [5, 8a, 14]. Finally, product 3a might be
generated via the migratory isomerization of the double bond by
the [Rh-H] species. The [Rh-H] species should be afforded by
intermediate B [8a].
Meng, G. R.; Szostak, M. Angew. Chem. Int. Ed. 2015, 54,
4518.
10) Patureau, F. W.; Besset, T.; Glorius, F. Angew. Chem. Int. Ed.
011, 50, 1064.
1
(
(
2
11) Zhang, H. Z.; Xu, X. L.; Chen, H. Y.; Ali, S.; Wang, D.; Yu, J.
W.; Xu, T.; Nan, F. J. Acta Pharmacologica Sinica. 2015, 36,
1
137.
12) (a) Patureau, F.; Glorius, F. J. Am. Chem. Soc. 2010, 132, 9982.
b) Tsai, A. S.; Brasse, M.; Bergman, R. G.; Ellman, J. A. Org.
(
(
Lett. 2011, 13, 540. (c) Gensch, T.; Vásquez-Céspedes, S.; Yu,
D. G.; Glorius, F. Org. Lett. 2015, 17, 3714. (d) Manikandan,
R.; Jeganmohan, M. Org. Biomol. Chem., 2016, 14, 7691.
13) Fukui, Y.; Liu, P.; Liu, Q.; He, Z. T.; Wu, N. Y.; Tian, P.; Lin.
G. Q.; J. Am. Chem. Soc. 2014, 136, 15607.
14) (a) Zhu, G. X.; Lu, X. Y. Organometallics. 1995, 14, 4899. (b)
Zhang, Z. G.; Lu, X. Y.; Xu, Z. R.; Zhang, Q. H.; Han, X. L.
Organometallics. 2001, 20, 3724. (c) Zhang, Q. H.; Lu, X. Y. J.
Am. Chem. Soc. 2000, 122, 7604. (d) Zhang, Q. H.; Lu, X. Y.;
Han, X. L. J. Org. Chem. 2001, 66, 7676. (e) Ohmiya, H.;
Makida, Y.; Tanaka, T.; Sawamura, M. J. Am. Chem. Soc.
(
(
Scheme 4. Possible Mechanism
2
008, 130, 17276.
Conclusions
(15) Lebedev, A. T.; Alekseeva, T. N.; Kutateladze, T. G.;
Mochalov, S. S.; Shabarov, Y. S.; Petrosyan, V. S. Org. Mass.
Spectrom. 1989, 24, 149.
In summary, we have been developed a Rh-catalyzed
selective oxidative Heck reaction of primary benzamides with
allylic esters. Under standard reaction conditions, a variety of
substrates underwent the reaction successfully to give
corresponding products in moderate to good yields. Further
work to extend the scope and application of this reaction is
currently underway.
(16) Typical Procedure: Under nitrogen atmosphere, an oven-dried
reaction vessel was charged with benzamide (1a, 0.4 mmol),
allyl
benzoate
(2a,
0.2
mmol),
bis[(pentamethylcyclopentadienyl) dichlororhodium] (5 mol%),
silver hexafluoroantimonate (20 mol%), iron (III) fluoride (50
mol%), tri-tert-butylphosphine tetrafluoroborate(10 mol%) and
DCE (2 mL). The vessel was sealed and heated at 100 °C (oil
bath temperature) for 16
temperature. The reaction mixture was filtered and washed
h and then cooled to room
Acknowledgments