F. Fang et al.
form Fe(CO)4L monomer species [46–50]. In the pre-
sent case, it was very likely that Fe2(CO)9 reacted with
C6H4-o-(NCH2PPh2)2BH through phosphorus coordina-
tion followed by oxidative addition of the B-H bond to
the iron center to form a PBP pincer iron hydride complex
C6H4-o-(NCH2PPh2)2BFe(H)(CO)2 (1) (Scheme 1). Similar
reactivity was reported by Ke, Langer and co-workers for
the reactions between Fe(CO)5 and (PR2XPR2)2B(H)2Br
(X = NH, CH2; R = Ph, Et), in which a series of cationic
PBP pincer iron complexes, [(PR2XPR2)2B(H)Fe(H)
(CO)2]+, formed [51]. The ruthenium counterpart of
complex (1), C6H4-o-(NCH2PPh2)2BRu(H)(CO)2 (2),
Acknowledgements This work was supported by the National Natural
Science Foundation of China (Grant Nos. 21571052, U1804253 and
21771057).
Declarations
Conflict of interest The authors declare that they have no confict of
interest.
1
References
was previously reported by Hill and co-workers. The H
NMR spectrum for complex 2 showed a sharp triplet at
−8.20 ppm (2JH-P = 23 Hz) for the hydride. X-ray crys-
tallography experiment of 2 showed two cis-CO ligands
coordinated to the metal center [52]. The formation of
complex 1 in the present system was confrmed by HRMS
(see Supporting Information). The reactions were likely
catalyzed by complex 1; detailed mechanistic investiga-
tion including further characterization of complex 1 is in
progress in our laboratory.
1. Roy SR, Sau SC, Mandal SK (2014) J Org Chem 79:9150–9160
2. Kumar G, Muthukumar A, Sekar G (2017) Eur J Org Chem
2017:4883–4890
3. Bhattacharya P, Krause JA, Guan H (2011) Organometallics
30:4720–4729
4. Bhattacharya P, Krause JA, Guan H (2014) Organometallics
33:6113–6121
5. Huang S, Zhao H, Li X, Wang L, Sun H (2015) RSC Adv
5:15660–15667
6. Zhao H, Sun H, Li X (2014) Organometallics 33:3535–3539
7. Tondreau AM, Lobkovsky E, Chirik PJ (2008) Org Lett
10:2789–2792
8. Zuo Z, Zhang L, Leng X, Huang Z (2015) Chem Commun
51:5073–5076
9. Tondreau AM, Darmon JM, Wile BM, Floyd SK, Lobkovsky E,
Chirik PJ (2009) Organometallics 28:3928–3940
10. Inagaki T, Phong LT, Furuta A, Ito J-I, Nishiyama H (2010) Chem
Eur J 16:3090–3096
4 Conclusions
In conclusion, we have successfully used Fe2(CO)9/C6H4-
o-(NCH2PPh2)2BH as a pre-catalyst for hydrosilylation
of aldehydes and ketones under a solvent-free condi-
tion. The reaction is highly efcient and tolerant of many
functional groups such as MeO, halogens, CN and C=C;
the corresponding alcohols have been isolated in good to
excellent yields following basic hydrolysis of the result-
ant hydrosilylation products. The reaction is likely cata-
lyzed by an in situ generated PBP iron hydride complex
C6H4-o-(NCH2PPh2)2BFe(H)(CO)2. The present work rep-
resents a good example of developing greener catalytic
processes for important chemical transformations based
on environmentally benign earth-abundant frst-row tran-
sition metals and is of relevance to green and sustainable
chemistry.
11. Inagaki T, Ito A, Ito J-I, Nishiyama H (2010) Angew Chem Int Ed
49:9384–9387
12. Bleith T, Wadepohl H, Gade LH (2015) J Am Chem Soc
137:2456–2459
13. Lin H-J, Lutz S, O’Kane C, Zeller M, Chen C-H, Assil TA, Lee
W-T (2018) Dalton Trans 47:3243–3247
14. Langlotz BK, Wadepohl H, Gade LH (2008) Angew Chem
120:4748–4752
15. Hosokawa S, Ito J-I, Nishiyama H (2010) Organometallics
29:5773–5775
16. Wu S, Li X, Xiong Z, Xu W, Lu Y, Sun H (2013) Organometallics
32:3227–3237
17. Gallego D, Inoue S, Blom B, Driess M (2014) Organometallics
33:6885–6897
18. Metsänen TT, Gallego D, Szilvási T, Driess M, Oestreich M
(2015) Chem Sci 6:7143–7149
19. Qi X, Zhao H, Sun H, Li X, Fuhr O, Fenske D (2018) New J Chem
42:16583–16590
20. Bézier D, Jiang F, Roisnel T, Sortais J-B, Darcel C (2012) Eur J
Inorg Chem 2012:1333–1337
21. Wekesa FS, Arias-Ugarte R, Kong L, Sumner Z, McGovern GP,
Findlater M (2015) Organometallics 34:5051–5056
22. Ruddy AJ, Kelly CM, Crawford SM, Wheaton CA, Sydora OL,
Small BL, Stradiotto M, Turculet L (2013) Organometallics
32:5581–5588
PPh2
CO
PPh2
N
N
N
N
toluene
RT
+
Fe2(CO)9
B
Fe CO
B
H
23. Flückiger M, Togni A (2011) Eur J Org Chem 2011:4353–4360
24. Hashimoto T, Urban S, Hoshino R, Ohki Y, Tatsumi K, Glorius
F (2012) Organometallics 31:4474–4479
H
PPh2
PPh2
1
25. Warratz S, Postigo L, Royo B (2013) Organometallics 32:893–897
26. Nesbit MA, Suess DML, Peters JC (2015) Organometallics
34:4741–4752
Scheme 1 Reaction of Fe2(CO)9 with C6H4-o-(NCH2PPh2)2BH
1 3