Please do not adjust margins
Green Chemistry
Page 5 of 7
Journal Name
COMMUNICATION
Foltz, H. B. Woodruff, J. M. Mata, S Hernandez and S.
Mochales, Science, 1969, 166 122; (b) F. John, N‐
Phosphonomethylglycine phytotoxicant compositions. U.S.
Patent 3799758, 1974; (c) G. Hoerlein, Rev. Environ. Contam.
Toxicol., 1994, 138, 73.
Chen, L. Yu, J. Chen and X. Hu, Green DCOheI:m10..,1023091/5C,8G17C,020973714G;
(e) Q. Xu, H. Xie, E.‐L. Zhang, X. Ma, J. Chen, X.‐C. Yu and H. Li,
Green Chem., 2016, 18, 3940; (f) Y. Yang, Z. Ye, X. Zhang, Y.
Zhou, X. Ma, H. Cao, J. Bao, H. Li, L. Yu, and Q. Xu, Org.
Biomol. Chem. 2017, 15, 9638; (g) X. Ma, L. Yu, C. Su, Y. Yang,
H. Li and Q. Xu, Adv. Synth. Catal., 2017, 359, 1649.
,
3
4
(a) P. J. Murphy, Organophosphorus Reagents; Oxford
University Press: Oxford, UK, 2004; (b) M. Mikolajczyk and P.
Balczewski Top. Curr. Chem., 2003, 223, 161.
12 Phosphite P(OEt)2(OCH2Ph) formed via transesterification
was also observed in 28% GC yield with trace double
transesterified P(OEt)(OCH2Ph)2 (ref. 13). Traces of
EtP(O)(OEt)2 and PhCH2P(O)(OEt)(OCH2Ph) derived from the
isomerization of 2a and P(OEt)(OCH2Ph)2 were also observed.
(a) T. Baumgartner and R. Réau, R. Chem. Rev., 2006, 106
,
4681; (b) C. Queffélec, M. Petit, P. Janvier, D. A. Knight and B.
Bujoli, Chem. Rev., 2012, 112, 3777; (c) J. L. Swanson, PUREX
Process Flowsheets, in: Science and Technology of Tributyl
Phosphate (Eds. W. W. Schulz, L. L. Burger, J. D. Navratil and 13 Transesterification of phosphorus compounds with alcohols:
K. P. Bender), CRC Press: Boca Raton, Fla, 1984; (d) A. Suresh,
T. G. Srinivasan and P. R. V. Rao, Solvent Extr. Ion Exc., 1994,
12, 727; (e) C. A. Wilkie, A. B. Morgan and G. L. Nelson, Fire
(a) F. W. Hoffmann, R. J. Ess and R. P. Usingef, Jr., J. Am.
Chem. Soc., 1956, 78, 5817; (b) F. W. Hoffmann, R. G. Roth
and T. C. Simmons, J. Am. Chem. Soc., 1958, 80, 5937.
and Polymers V: Materials and Concepts for Fire Retardancy, 14 See the †ESI for details.
American Chemical Society, 2009, pp 205‐248; (f) J. Green, in: 15 The reaction was also investigated under other conditions (at
Fire Retardancy of Polymeric Materials (Eds. A. F. Grand and
C. A. Wilkie), Marcel Dekker: New York, 2000, pp 147−170.
lower temperatures, in solvents, using more or less loadings
of 2a), but no better results were obtained.
5
(a) A. L. Schwan, Chem. Soc. Rev., 2004, 33, 218; (b) C. S. 16 P(OEt)2(OCH2Ph) (ref. 13) was observed as the major product
Demmer, N. Krogsgaard‐Larsen and L. Bunch, Chem. Rev.,
in 85% GC yield (see also eq. 4).
2011, 111, 7981; (c) J.‐L. Montchamp, Acc. Chem. Res., 2014, 17 We appreciate one of the reviewers for this kind suggestion.
47, 77; (d) F. M. J. Tappe, V. T. Trepohl and M. Oestreich,
Synthesis, 2010, 3037; (e) R. Engel and J. I. Cohen, Synthesis
of Carbon‐Phosphorus Bonds, CRC Press, New York, 2004; (f)
R. A. Stockland, Practical Functional Group Synthesis; John
Wiley & Sons, Waukegan, IL, 2016, Chapter 4, pp 219‐470; (g)
However, possibly due to the ready transesterification
reaction of and that can even occur at room temperature
1
2
(see ref. 24 and ESI), as we observed, there is no need to
†
distill out byproduct EtOH from the reaction vessel using an
unsealed reactor.
C. A. Bange and R. Waterman, Eur. Chem. J., 2016, 22, 12598; 18 Most possibly due to the close steric hindrance and close
(h) R. Waterman, Chem. Soc. Rev., 2013, 42, 5629; (i) L.‐B.
Han and M. Tanaka, Chem. Commun., 1999, 395; (j) Q. Xu
and L.‐B. Han, J. Organomet. Chem., 2011, 696, 130.
reactivities of the Et and aliphatic alkyl groups, nucleophilic
attack of I‐ at the CH2 of Et and aliphatic alkyl groups
(according to the proposed mechanism) both occurred to
give a mixture of the desired product and byproduct diethyl
ethylphosphonate in the reactions of P(OEt)3. In contrast, the
use of P(Oi‐Pr)3 could successfully suppress the same side
reaction of P(Oi‐Pr)3 (the nucleophilic attack of I‐ at the CH of
i‐Pr) and generation of the byproduct, most likely due to the
greater steric hindrance and much lower reactivity of the
more bulky i‐Pr than the aliphatic alkyl groups.
6
7
(a) B. A. Arbuzov, Pure Appl. Chem., 1964, 9, 307; (b) A. K.
Bhattacharya and G. Thyagarajan, Chem. Rev., 1981, 81, 415.
(a) P.‐Y. Renard, P. Vayron, E. Leclerc, A. Valleix and C.
Mioskowski, Angew. Chem. Int. Ed., 2003, 42, 2389; (b) P.‐Y.
Renard, P. Vayron and C. Mioskowski, Org. Lett., 2003, 5,
1661; (c) W. Dabkowski, A. Ozarek, S. Olejniczak, M. Cypryk, J.
Chojnowski and J. Michalski Chem. Eur. J., 2009, 15, 1747.
8
9
(a) R. J. Barney, R. M. Richardson and D. F. Wiemer, J. Org. 19 B. De Filippis, A. Ammazzalorso, M. Fantacuzzi, L. Giampietro,
Chem., 2011, 76, 2875; (b) R. M. Richardson and D. F. C.Maccallini and R. Amoroso, ChemMedChem, 2017, 12, 558.
Wiemer, Org. Synth., 2012, 90, 145; (c) G. G. Rajeshwaran, M. 20 N. J. Lawrence and F. Muhammad, Tetrahedron, 1998, 54
Nandakumar, R. Sureshbabu and A. K. Mohanakrishnan, Org. 15361.
Lett., 2011, 13, 1270; (d) N. Iranpoor, H. Firouzabadi, K. R. 21 Due to its sensitive nature toward air, generation of 7a was
,
Moghadam and E. Etemadi‐Davan, Asian J. Org. Chem., 2015,
, 1289.
confirmed by transformation into phosphonium salt
[PPh2(CH2Ph)2]Br.
4
(a) Q. Xu, C.‐Q. Zhao and L.‐B. Han, J. Am. Chem. Soc., 2008, 22 Since the reaction of
1 and 2 is a reversible equilibrium (ref.
130, 12648; (b) Q. Xu and L.‐B. Han, Org. Lett., 2006,
8
, 2099;
13), GC yield of 8a is not quantitative. Addition of n‐Bu4NI
could then drive the reaction to complete and effectively
gave 3a in a high yield.
(c) Q. Xu, R. Shen, Y. Ono, R. Nagahata, S. Shimada, M. Goto
and L.‐B. Han, Chem. Commun., 2011, 47, 2333; (d) Q. Xu, Y.‐
B. Zhou, C.‐Q. Zhao, S.‐F. Yin and L.‐B. Han, Mini‐Rev. Med. 23 Similarly, the blank reaction of 1c and 4a also afforded
Chem., 2013, 13, 824; (e) Q. Li, T. Chen, Q. Xu and L.‐B. Han,
Chem. Eur. J., 2016, 22, 6213.
10 (a) J. A. Watson and J. M. J. Williams, Science, 2010, 329, 635;
(b) G. E. Dobereiner and R. H. Crabtree, Chem. Rev., 2010,
mainly transesterified Ph2POCH2C6H4OMe (ref. 13) as
isolated and confirmed by NMR analysis. Ph2POCH2C6H4OMe
was then transformed into 5c catalyzed by n‐Bu4NI. See the
†
ESI for details.
110, 681; (c) G. Guillena, D. J. Ramón and M. Yus, Chem. Rev., 24 This is also supported by a room temperature reaction of 1a
2010, 110, 1611; (d) S.‐Y. Zhang, F.‐M. Zhang and Y.‐Q. Tu, and 2a that gave 8a as the sole product.
Chem. Soc. Rev., 2011, 40, 1937; (e) E. Emer, R. Sinisi, M. G. 25 The reaction of 1a and n‐Bu4NBr in the presence of
Capdevila, D. Petruzziello, F. De Vincentiis and P. G. Cozzi,
Eur. J. Org. Chem., 2011, 647; (f) J. Muzart, Tetrahedron,
2005, 61, 4179; (g) X. Ma, C. Su and Q. Xu, N‐Alkylation by
hydrogen autotransfer reactions, in: Hydrogen transfer
reactions: reductions and beyond (Eds.: G. Guillena and D. J.
Ramón), Topics in Current Chemistry, Vol. 374, Springer,
Berlin, Heidelberg, 2016, pp 1–74.
quantitative 2a readily afforded considerable yields of ethers
(PhCH2)2O and PhCH2OEt (right), which should be produced
by the reaction of 1a and byproduct EtOH with the in situ
generated PhCH2Br (ref. 11d). In contrast, no reaction
occurred at all in the blank reaction of 1a and n‐Bu4NBr
without 2a (left), revealing that PhCH2Br can not be
generated from a blank reaction of 1a and n‐Bu4NBr. Thus,
the only way to generate PhCH2Br is via the proposed
mechanism in the presence of 2a (Scheme 2).
11 (a) Q. Xu and Q. Li, Chin. J. Org. Chem., 2013, 33, 18; (b) Q.
Xu, J. Chen, H. Tian, X. Yuan, S. Li, C. Zhou and J. Liu, Angew.
Chem. Int. Ed., 2014, 53, 225; (c) Q. Xu, Q. Li, X. Zhu and J.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1‐3 | 5
Please do not adjust margins