Inorganic Triphenylphosphine

Article abstract of DOI:10.1002/anie.201810366

A completely inorganic version of one of the most famous organophosphorus compounds, triphenylphosphine, has been prepared. A comparison of the crystal structures of inorganic triphenylphosphine, PBaz₃ (where Baz=B₃H₂N₃H₃) and PPh₃ shows that they have superficial similarities and furthermore, the Lewis basicities of the two compounds are remarkably similar. However, their oxygenation and hydrolysis reactions are starkly different. PBaz₃ reacts quantitatively with water to give PH₃ and with the oxidizing agent ONMe₃ to give the triply-O-inserted product P(OBaz)₃, an inorganic version of triphenyl phosphite; a corresponding transformation with PPh₃ is inconceivable. Thermodynamically, what drives these striking differences in the chemistry of PBaz₃ and PPh₃ is the great strength of the B?O bond.

Full text of DOI:10.1002/anie.201810366

A Journal of the Gesellschaft Deutscher Chemiker
Angewandte
Chemie
International Edition
www.angewandte.org
Accepted Article
Title: Inorganic Triphenylphosphine
Authors: Paul Pringle, Adam Gorman, Hazel Sparkes, Tom Young,
Jonathan Bailey, and Natalie Fey
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: Angew. Chem. Int. Ed. 10.1002/anie.201810366
Angew. Chem. 10.1002/ange.201810366
Link to VoR: http://dx.doi.org/10.1002/anie.201810366
http://dx.doi.org/10.1002/ange.201810366

10.1002/anie.201810366
Angewandte Chemie International Edition
COMMUNICATION
Inorganic Triphenylphosphine
Adam D. Gorman, Jonathan A. Bailey, Natalie Fey, Tom A. Young, Hazel A. Sparkes, Paul G. Pringle*
Abstract: A completely inorganic version of one of the most famous
organophosphorus compounds, triphenylphosphine, has been
prepared. A comparison of the crystal structures of inorganic
triphenylphosphine, PBaz3 (where Baz = B3H2N3H3) and PPh3 shows
that they have superficial similarities and furthermore, the Lewis
basicities of the two compounds are remarkably similar. However,
their oxygenation and hydrolysis reactions are starkly different.
PBaz3 reacts quantitatively with water to give PH3 and with the
oxidizing agent ONMe3 to give the triply-O-inserted product
only been partially characterised in situ as part of a mixture of
products formed in the photochemical oxidation of borazine.[37] In
addition, no borazines that contain P–B bonds have been
reported which may be due to the anticipated high reactivity of
the P–B bond.[38]
H
B
H
C
H
H
H
H
H
H
H
H
N
B
N
B
C
C
C
C
N
H
C
H
P(OBaz)3, an inorganic version of triphenyl phosphite;
a
corresponding transformation with PPh3 is inconceivable.
Thermodynamically, what drives these striking differences in the
chemistry of PBaz3 and PPh3 is the great strength of the B–O bond.
Borazine
Benzene
Photochemistry
The diatomic fragments BN and CC are isoelectronic and the
chemical consequences of this simple relationship have been
appreciated ever since the 1926 discovery of borazine which is
isoelectronic to benzene and dubbed "inorganic benzene"
(Figure 1).[1] The substitution of a BN unit for a CC in an organic
molecule has a transformative effect on the properties of the
compound as illustrated by the three comparisons given in
B
N
Blue light emission
em = 450 nm
UV light emission
em = 347 nm
l
l
Figure
1
from the fields of photochemistry,[2–7] medicinal
Medicinal chemistry
chemistry[8–13] and hydrogen storage.[14–18]
N
Since BN and CC are considered to be isosteres, the
explanation for the sharply different properties of BN / CC
analogues most likely lies in differences in the bonding and
electronegativity. The energies and sizes of the atomic orbitals
formally combining to form the molecular orbitals of a CC bond
are self-evidently matched whereas the mismatched energies
and sizes of the atomic orbitals combining in the BN bond make
the -bonding dipolar and the -bonding weaker due to less
efficient overlap.[19–22] The result is that BN compounds are
generally kinetically and thermodynamically more reactive than
their CC analogues. Thus, borazine has superficial similarities
with benzene (e.g. both are colourless liquids under ambient
conditions) but the aromaticity of borazine, as determined
computationally and experimentally, is significantly lower than
the aromaticity of benzene (e.g. NICS values for benzene and
borazine are -11.5 and -2.1 respectively),[23–25] and the dominant
mechanisms by which they undergo substitution are
fundamentally different: electrophilic aromatic substitution for
benzene, addition-elimination for borazine.[26,27]
BH
EbDH substrate
EbDH inhibitor
Hydrogen storage
H
H
H
H
H
H
B
N
H
H
H
H
H
H
Solid below 104 °C
Gas above -89 °C
Figure 1. Examples of isoelectronic compounds featuring BN for CC
substitution.
B-trisubstituted borazines (Figure 2) are readily prepared
and their chemistry has been well studied[28–33] but the chemistry
of the less accessible B-monosubstituted borazines (XBaz,
Figure 2) has been little developed;[34–36] for example, 2-
hydroxyborazine (HOBaz), the borazine analogue of phenol, has
Figure 2. Examples of substituted borazines.
There are thousands of academic articles and patents featuring
PPh3 and globally it is produced on a multi-kiloton scale per
annum because of its multitude of applications.[39,40] We were
intrigued to know whether it would be possible to make
[a]
Dr. A. D. Gorman, Dr. J. A. Bailey, Dr. N. Fey, T. A. Young, Dr. H.
A. Sparkes, Prof. P. G. Pringle*
School of Chemistry
University of Bristol
Cantock’s Close, Bristol, BS8 1TS
E-mail: paul.pringle@bristol.ac.uk
"inorganic"
triphenylphosphine
(Figure
2,
tris(2-
borazinyl)phosphine; PBaz3) and if so, how its properties would
compare with "conventional" triphenylphosphine (PPh3). Here
we report the successful synthesis of PBaz3 and show that it has
Supporting information for this article is given via a link at the end
of the document
This article is protected by copyright. All rights reserved.

10.1002/anie.201810366
Angewandte Chemie International Edition
COMMUNICATION
Lewis basicity similar to that of PPh3 but the high reactivity of the
P–B bond leads to oxygenation chemistry that is unprecedented
with conventional phosphines.
and remains broad at high (+80 ˚C) temperatures, consistent
with the short quadrupolar relaxation times of, and unresolved
coupling to, the nine 11B/10B nuclei. The δP of PBaz3 is 200 ppm
to high field of PPh3 (δP = -5.0 ppm), and much closer to that of
P(SiMe3)3 (δP = -251 ppm) and PH3 (δP = -241 ppm) reflecting
the very different magnetic environments of the P atom in PBaz3
and PPh3. The 11B and 1H NMR spectra of PBaz3 show the
expected signals.
Synthesis and characterization of PBaz3. We have
previously shown that P–B bonds can be readily formed by a
chlorosilane elimination reaction between a chloroborane and a
silylphosphine.[41]
Pleasingly,
the
reaction
between
chloroborazine and P(SiMe3)3 produced PBaz3 quantitatively
(Scheme 1) according to multinuclear NMR spectroscopy (see
Supporting Information for details). The reaction was monitored
by 31P NMR spectroscopy which showed that the conversion of
P(SiMe3)3 to PBaz3 proceeded smoothly over 5 h via two
intermediates which are assigned to the monoborazinyl
(Me3Si)2PBaz and diborazinyl Me3SiPBaz2.
Crystals of PBaz3 suitable for X-ray crystallography were
obtained from its saturated solution in CH2Cl2 stored at -20 °C
and its crystal structure is shown in Figure 3 alongside the
structure of PPh3.[42] The molecular structure of PBaz3 shows a
propeller-like orientation of the planar borazinyl substituents with
near C3 symmetry and a pyramidal geometry at phosphorus.
Ostensibly the structures of PBaz3 and PPh3 are similar but they
differ significantly in the details: (1) The P–B bond lengths in
PBaz3 are ca. 0.1 Å longer than the P–C bond lengths in PPh3
paralleling the difference in the covalent radii (rC = 0.73(2) Å, rB =
0.84(3) Å). (2) The geometry at P in PBaz3 is considerably
flattened, in accord with Bent's Rule[43] which predicts that the p-
character of P–X π-bonds (e.g. in PX3 where X = F, OR, NR2,
CR3, BR2) should decrease with decreasing electronegativity of
X; the flattening at P is also consistent with some π-character in
the P–B bonds (see below). (3) The orientation of the rings in
PBaz3 is less propeller-like than in PPh3 as is clear by
comparison of the side-on views in Figure 3 which show that the
acute angle (56˚) between the planes of the rings in PBaz3
contrasts with the approximately orthogonal (82˚) rings in PPh3.
(4) The long P–B bonds make the P atom less crowded in PBaz3
than in PPh3 as shown by the calculated crystallographic cone
angles[44] of 137˚ (PBaz3) and 154˚ (PPh3).
Scheme 1. Synthesis of tris(2-borazinyl)phosphine (PBaz3).
The white, malodorous, solid PBaz3 was isolated in yields of
up to 97% simply by removal of the volatiles. The 31P NMR
spectrum of solutions of PBaz3 in THF under argon at ambient
temperatures is unchanged over a period of one month. The 31P
NMR signal at -205 ppm for PBaz3 is very broad (w1/2 = 340 Hz)
Figure 3. Molecular structures of PBaz3 and PPh3.[42] Two views of the structures are given: (a) along the C3 axis and (b) perpendicular to the C3 axis, to facilitate
the comparison. (c) Plots of the HOMOs of PBaz3 and PPh3 (isovalues 0.05). Selected bond lengths (Å) and angles: P1-B1 1.923(2), P1-B4 1.9230(19), P1-B7
1.9255(18), B1-P1-B4 106.34(8), B4-P1-B7 107.78(8), B1-P1-B7 107.44(8), B1-P1-B7-N9 52.94(11), B7-P1-B4-N6 55.98(10), B4-P1-B1-N3 57.74(10).
This article is protected by copyright. All rights reserved.

10.1002/anie.201810366
Angewandte Chemie International Edition
COMMUNICATION
DFT calculations have been carried out (PBE0-D3BJ/cc-pVTZ)
in order to compare the electronic structures of PBaz3 with PPh3.
Both calculated structures closely matched the structures
obtained by X-ray crystallography (see SI). The surface contour
maps of the canonical HOMOs for PBaz3 and PPh3 are clearly
identifiable as the lone pairs on the P atoms (Figure 3c) and the
calculated energies of these orbitals are similar: -6.165 eV
(PPh3) and -6.321 eV (PBaz3). NBO calculations show that the
HOMO of PBaz3 has 64% p-character which is significantly more
than the 54% for PPh3; the greater p-character is also apparent
from the shapes of the HOMO orbitals (Figure 3c). The
calculated bond indices for P–B in PBaz3 (1.07) and P–C in
PPh3 (0.92) support the idea that there is a small amount of P–B
-bonding present in PBaz3.[45]
Reaction of PBaz3 with BH3. Addition of H3B∙THF to PBaz3
generated a product that has been characterised in solution by
31P and 11B NMR spectroscopy and assigned the structure
Baz3P∙BH3 (Scheme 2); the analogous Ph3P∙BH3 is formed
similarly from H3B∙THF and PPh3.[46] The 31P and 11B NMR
signals for the Baz3P∙BH3 are at δP = -171 and δB = -42 ppm
which correspond to coordination chemical shifts of δP = +34
and δB = -41 ppm; these values are similar to those for
Ph3P∙BH3 (ΔδP = +26 and ΔδB = -38 ppm).
In order to determine the relative Lewis base strengths of
PBaz3 and PPh3, the position of the equilibrium shown in
Scheme 2 has been investigated by 31P NMR spectroscopy.
When Ph3P∙BH3 and PBaz3 or Baz3P∙BH3 and PPh3 were mixed
in THF, an equilibrium was slowly established over several
hours in favour of Ph3P∙BH3 and integration of the 31P NMR
signals for the constituents led to an estimate of the equilibrium
constant K to be ~140. Since this equates to a ΔG ~ 3 kcal mol-1,
it is concluded that the Lewis basicity of PPh3 is similar but
slightly greater than PBaz3. Our calculations (DLPNO-
CCSD(T)/def2-TZPP//PBE0-D3BJ/def2-SVP) show that the
borane binding enthalpy (calculated in vacuo and neglecting
entropic corrections) of PPh3 (34 kcal mol-1) is greater than that
of PBaz3 (26 kcal mol-1) in line with the experimental observation
favoring PPh3∙BH3.
on the basis of the 11B NMR spectrum which showed a doublet
at +30 ppm (1JBH = 139 Hz) and a singlet at +24 ppm in a 2:1
intensity ratio.
When a sub-stoichiometric amount of H2O was added to
PBaz3, the 31P NMR spectrum of the resulting solution contained
two species in addition to PBaz3 and PH3 and these are
assigned, on the basis of their 31P parameters, to the
intermediate secondary phosphine Baz2PH (δP = -203 ppm,
doublet, JPH = 200 Hz) and primary phosphine BazPH2 (δP
= -228 ppm, triplet, JPH = 203 Hz) (see SI); the JPH values for
Ph2PH (216 Hz) and PhPH2 (199 Hz) are similar to the
borazinylphosphine analogues. The hydrolysis of PBaz3 is
reminiscent of the hydrolysis of P(SiMe3)3 under the same
conditions to give HnP(SiMe3)3-n (n = 1-3; see SI for details); this
is an illustration of the similar reactivity of P–B and P–Si bonds
which can be viewed as a manifestation of the B/Si diagonal
relationship.
The Gibbs free energy change (ΔG) for the observed PBaz3
hydrolysis to PH3 was calculated to be -73 kcal mol-1 (using our
standard DLPNO-CCSD(T) approach) which is
a strong
thermodynamic driving force and almost 100 kcal mol-1 more
favourable than the ΔG calculated for the analogous
hypothetical PPh3 hydrolysis (+26 kcal mol-1, Scheme 3). This
contrasting outcome is attributed to B–O bonds (~130 kcal mol-1)
being much stronger than C–O bonds (~85 kcal mol-1).
– 73
PH3
PH3
PBaz3
PPh3
+
+
3 H2O
3 H2O
+
+
3 BazOH
3 PhOH
+26
O
– 84
– 52
+ 0.5 O2
PBaz3
Baz2P OBaz
PBaz3
PPh3
O
– 57
– 77
+ 0.5 O2
PPh3
Ph2P OPh
Scheme 3. Thermodynamics of hydrolysis and oxygenation of PPh3 and
PBaz3. Values of ∆G in kcal mol-1; the solid reaction arrows indicate the
experimentally observed reactions.
We have previously shown that O atoms can be inserted into the
P–B bonds of borylphosphines by treatment with ONMe3; this
occurred even when the P lone pair of the borylphosphine was
coordinated to Rh.[47] It was therefore of interest to investigate
whether inorganic triphenylphosphine, PBaz3 could be converted
directly to inorganic triphenyl phosphite, P(OBaz)3 (Scheme 2).
The in situ 31P{1H} NMR spectrum of the PBaz3/ONMe3 reaction
mixture showed, after 5 min, a sharp singlet at δP +119 ppm (cf.
for P(OPh)3, δP 129 ppm) as the only P-containing product; this
is a change in 31P NMR shift of over +300 ppm from the signal of
PBaz3. Consistent with the structure of P(OBaz)3, the 11B NMR
spectrum displayed two broad signals at +31 ppm (1JBH ~ 125
Hz) and +23 ppm in a 2:1 ratio.
Treatment of PPh3 with ONMe3 gives O=PPh3 whereas no
similar reaction occurred to give O=PBaz3 and the only observed
product was the phosphite P(OBaz)3. In order to probe the
source of this sharp difference in chemistry, calculations were
carried out on two alternative monooxygenation reactions (with
O2) that produce phosphine oxide or phosphinite (Scheme 3).
Scheme 2. Reactions of PBaz3 with BH3, H2O and ONMe3.
Hydrolysis and oxygenation of PBaz3. The reactivity of the P–
B bonds in PBaz3 towards water and oxidizing agents is very
different from the P–C bonds in PPh3. For example, while PPh3
is completely inert to water, PBaz3 is extremely moisture
sensitive. PBaz3 reacts rapidly and quantitatively with water to
give PH3 (δP = -241 ppm, quartet, JPH = 187 Hz) and a species
tentatively assigned to 2-hydroxyborazine (HOBaz, Scheme 2)
These calculations predict that there would be
a strong
thermodynamic preference for phosphinite formation with PBaz3
but phosphine oxide formation with PPh3. Calculated bond
This article is protected by copyright. All rights reserved.

10.1002/anie.201810366
Angewandte Chemie International Edition
COMMUNICATION
dissociation enthalpies indicate that the P–B bond in PBaz3 (90
kcal mol-1) is stronger than the P–C bond in PPh3 (81 kcal mol-1)
and therefore the unconventional oxidation chemistry of PBaz3 is
driven by the high B–O bond strength.
Chem. Vol. 49 (Eds.: E. Fernández, A. Whiting), Springer
International Publishing, 2015, pp. 153–220.
A. Rossin, M. Peruzzini, Chem. Rev. 2016, 116, 8848–8872.
Z. Mo, A. Rit, J. Campos, E. L. Kolychev, S. Aldridge, J. Am. Chem.
Soc. 2016, 138, 3306–3309.
[17]
[18]
The chemistry of borazine has intrigued chemists for over 90
years. The synthesis of triborazinylphosphine (PBaz3), an
inorganic analogue of triphenylphosphine (PPh3), is notable
because it is the most elaborate molecular borazine so far
reported and the first borazine to contain a B–P bond. The
structures and Lewis basicity of PBaz3 and PPh3 are similar but
their oxygenation and hydrolysis chemistry could hardly be more
different. For example, PBaz3 catches fire in air (presumably due
to the formation of PH3) while PPh3 is indefinitely air-stable even
in solution. Controlled oxidation transforms PBaz3 into "inorganic
triphenyl phosphite", P(OBaz)3 by three O insertions into the P–
B bonds while PPh3 produces simply triphenylphosphine oxide.
These striking differences in chemistry are thermodynamically
driven by the very high B–O bond strength. The extreme
sensitivity of PBaz3 to air and moisture producing PH3, precludes
many applications for PBaz3 in catalysis but its synthesis opens
up the possibility of developing more stable ligands containing a
single borazinyl substituent and the prospect of producing
unchartered borazines that contain B bonded to other 2nd row
elements such as Si and S.
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
W. Shen, M. Li, Y. Li, S. Wang, Inorganica Chim. Acta 2007, 360,
619–624.
A. K. Phukan, A. K. Guha, B. Silvi, Dalt. Trans. 2010, 39, 4126–
4137.
D. Wu, L. Kong, Y. Li, R. Ganguly, R. Kinjo, Nat. Commun. 2015,
6:7340, DOI 10.1038/ncomms8340.
H. Braunschweig, A. Damme, R. D. Dewhurst, A. Vargas, Nat.
Chem. 2013, 5, 115–121.
R. Islas, E. Chamorro, J. Robles, T. Heine, J. C. Santos, G. Merino,
Struct. Chem. 2007, 18, 833–839.
D. E. Bean, P. W. Fowler, J. Phys. Chem. A 2011, 115, 13649–
13656.
B. Kiran, A. K. Phukan, E. D. Jemmis, Inorg. Chem. 2001, 40,
3615–3618.
A. W. Laubengayer, O. T. Beachley, R. F. Porter, Inorg. Chem.
1965, 4, 578–582.
M. K. Kesharwani, M. Suresh, A. Das, B. Ganguly, Tetrahedron Lett.
2011, 52, 3636–3639.
C. A. Brown, A. W. Laubengayer, J. Am. Chem. Soc. 1955, 77,
3699–3700.
Keywords: Main Group Elements • Phosphorus • Boron •
Inorganic Chemistry • Structure Elucidation
C. K. Narula, R. Schaeffer, A. Datye, R. T. Paine, Inorg. Chem.
1989, 28, 4053–4055.
[1]
[2]
A. Stock, E. Pohland, Ber. Dtsch. Chem. Ges. 1926, 59, 2215–2223.
M. J. D. Bosdet, C. A. Jaska, W. E. Piers, T. S. Sorensen, M.
Parvez, Org. Lett. 2007, 9, 1395–1398.
[30]
[31]
E. Framery, M. Vaultier, Heteroat. Chem. 2000, 11, 218–225.
Y. Yamamoto, K. Miyamoto, J. Umeda, Y. Nakatani, T. Yamamoto,
N. Miyura, J. Organomet. Chem. 2006, 691, 4909–4917.
H. Braunschweig, H. Green, K. Radacki, K. Uttinger, Dalt. Trans.
2008, 3531–3534.
[3]
[4]
A. J. V Marwitz, A. N. Lamm, L. N. Zakharov, M. Vasiliu, D. A. Dixon,
S. Liu, Chem. Sci. 2012, 3, 825–829.
[32]
[33]
X. Y. Wang, A. Narita, X. Feng, K. Müllen, J. Am. Chem. Soc. 2015,
137, 7668–7671.
D. Bonifazi, F. Fasano, M. M. Lorenzo-Garcia, D. Marinelli, H.
Oubaha, J. Tasseroul, Chem. Commun. 2015, 51, 15222–15236.
O. T. Beachely, Inorg. Chem. 1969, 8, 2665–2667.
O. T. Beachely, Inorg. Chem. 1969, 8, 981–985.
O. T. Beachley, T. R. Durkin, Inorg. Chem. 1973, 12, 1128–1130.
G. H. Lee, R. F. Porter, Inorg. Chem. 1967, 6, 648–652.
J. A. Bailey, P. G. Pringle, Coord. Chem. Rev. 2015, 297–298, 77–
90.
[5]
[6]
[7]
X. Y. Wang, J. Y. Wang, J. Pei, Chem. Eur. J. 2015, 21, 3528–3539.
H. Huang, Z. Pan, C. Cui, Chem. Commun. 2016, 52, 4227–4230.
Z. Liu, J. S. A. Ishibashi, C. Darrigan, A. Dargelos, A. Chrostowska,
B. Li, M. Vasiliu, D. A. Dixon, S. Y. Liu, J. Am. Chem. Soc. 2017,
139, 6082–6085.
[34]
[35]
[36]
[37]
[38]
[8]
C. Baldock, J. B. Rafferty, S. E. Sedelnikova, P. J. Baker, A. R.
Stuitje, A. R. Slabas, T. R. Hawkes, D. W. Rice, Science 1996, 274,
2107–2110.
[39]
[40]
G. Wittig, U. Schollkopf, Chem. Ber. 1954, 87, 1318–1330.
D. Evans, J. A. Osborn, G. Wilkinson, J. Chem. Soc. A Inorg. Phys.
Theor. 1968, 3133–3142.
[9]
L. Liu, A. J. V Marwitz, B. W. Matthews, S.-Y. Liu, Angew. Chem. Int.
Ed. 2009, 48, 6817–6819.
[41]
[42]
J. A. Bailey, M. Ploeger, P. G. Pringle, Inorg. Chem. 2014, 53,
7763–7769.
[10]
[11]
[12]
[13]
[14]
[15]
D. H. Knack, J. L. Marshall, G. P. Harlow, A. Dudzik, M. Szaleniec,
S. Liu, J. Heider, Angew. Chem. Int. Ed. 2013, 52, 2599–2601.
F. J. R. Rombouts, F. Tovar, N. Austin, G. Tresadern, A. A.
Trabanco, J. Med. Chem. 2015, 58, 9287–9295.
H. Lee, M. Fischer, B. K. Shoichet, S. Y. Liu, J. Am. Chem. Soc.
2016, 138, 12021–12024.
B. Ziemer, A. Rabis, H. U. Steinberger, Acta Crystallogr. Sect. C
2000, C56, e58–e59.
[43]
[44]
H. A. Bent, Chem. Rev. 1961, 61, 275–311.
T. E. Müller, D. M. P. Mingos, Transit. Met. Chem. 1995, 20, 533–
539.
P. Zhao, D. O. Nettleton, R. G. Karki, F. J. Zécri, S. Y. Liu,
ChemMedChem 2017, 12, 358–361.
[45]
[46]
[47]
E. N. Daley, C. M. Vogels, S. J. Geier, A. Decken, S. Doherty, S. A.
Westcott, Angew. Chem., Int. Ed. 2015, 54, 2121–2125.
M. L. Schirmer, S. Jopp, J. Holz, A. Spannenberg, T. Werner, Adv.
Synth. Catal. 2016, 358, 26–29.
A. Staubitz, A. P. M. Robertson, I. Manners, Chem. Rev. 2010, 110,
4079–4124.
G. Chen, L. N. Zakharov, M. Bowden, A. Karkamkar, S. M.
Whittemore, E. B. Garner, T. C. Mikulas, D. A. Dixon, T. Autrey, S.-
Y. Liu, J. Am. Chem. Soc. 2015, 137, 134–137.
J. A. Bailey, H. A. Sparkes, P. G. Pringle, Chem. Eur. J. 2015, 21,
5360–5363.
[16]
H. C. Johnson, T. N. Hooper, A. S. Weller, in Top. Organomet.
This article is protected by copyright. All rights reserved.

10.1002/anie.201810366
Angewandte Chemie International Edition
COMMUNICATION
COMMUNICATION
H
B
H
B
Inorganic versus organic: the
molecular structures and Lewis
basicities of triphenylphosphine and
tris(2-borazinyl)phosphine appear
similar but their hydrolysis and
oxygenation chemistry could hardly be
more contrasting.
Adam D. Gorman, Jonathan A. Bailey,
Natalie Fey, Tom A. Young, Hazel A.
Sparkes, Paul G. Pringle*
HN
HB
NH
B
HN
B
NH
BH
N
H
N
H
P
B
Page No. – Page No.
HN
HB
NH
BH
Inorganic Triphenylphosphine
N
H
This article is protected by copyright. All rights reserved.