Transition metal free catalytic hydroboration of aldehydes and aldimines by amidinato silane

Article abstract of DOI:10.1039/c6dt04893e

The transition metal free catalytic hydroboration of aldehydes and ketones is very limited and has not been reported with a well-defined silicon(iv) compound. Therefore, we chose to evaluate the previously reported silicon(iv) hydride [PhC(NtBu)₂SiHCl₂], (1) as a single component catalyst and found that it catalyzes the reductive hydroboration of a range of aldehydes with pinacolborane (HBpin) under ambient conditions. In addition, compound 1 can catalyze imine hydroboration. DFT calculation was carried out to understand the mechanism.

Full text of DOI:10.1039/c6dt04893e

View Article Online
View Journal
Dalton
Transactions
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: M. K. Bisai, S.
Pahar, T. Das, K. Vanka and S. S. Sen, Dalton Trans., 2017, DOI: 10.1039/C6DT04893E.
Volume 45 Number
1
7
January 2016 Pages 1–398
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Dalton
Transactions
An international journal of inorganic chemistry
www.rsc.org/dalton
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
author guidelines.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the ethical guidelines, outlined
in our author and reviewer resource centre, still apply. In no
event shall the Royal Society of Chemistry be held responsible
for any errors or omissions in this Accepted Manuscript or any
consequences arising from the use of any information it contains.
ISSN 1477-9226
PAPER
Joseph T. Hupp, Omar K. Farha et al.
Efficient extraction of sulfate from water using
framework
a Zr-metal–organic
rsc.li/dalton

Page 1 of 57
Dalton Transactions
View Article Online
DOI: 10.1039/C6DT04893E
Graphical Abstract
for
Transition metal free catalytic hydroboration of aldehydes and
aldimines by amidinato silane
a
a
b
b
a
Milan Kumar Bisai, Sanjukta Pahar, Tamal Das, Kumar Vanka* and Sakya S. Sen*
Benz-aimidinato dichlorosilane [PhC(NtBu) SiHCl ] has been reported to catalyze hydroboration
2
2
of aldehydes at room temperature and aldimines with slightly forcing conditions.

Please do not adjust margins
Dalton Transactions
Page 2 of 57
View Article Online
DOI: 10.1039/C6DT04893E
Dalton Transactions
Communication
Transition metal free catalytic hydroboration of aldehydes and
aldimines by amidinato silane
Received 00th January 20xx,
Accepted 00th January 20xx
a
a
b
b
a
Milan Kumar Bisai, Sanjukta Pahar, Tamal Das, Kumar Vanka* and Sakya S. Sen*
DOI: 10.1039/x0xx00000x
www.rsc.org/
The transition metal free catalytic hydroboration of aldehydes and ions promoted catalytic imine reduction and Diels−Alder
1
4a,b,g
F
ketones is very limited and has not been reported with a well- reactions
defined silicon(IV) compound. Therefore, we chose to evaluate the catalyzed aldehyde hydrosilylation
previously reported silicon(IV) hydride [PhC(NtBu) SiHCl ], (1) as a reported illustrating the potential of silicon compounds as
single component catalyst and found that it catalyzes the catalysts. Besides, there are recent theoretical and
reductive hydroboration of range of aldehydes with experimental reports on formylation of amines using a
pinacolborane (HBpin) at ambient conditions. In addition, comibation of CO
compound 1 can catalyze imine hydroboration. DFT calculation Cantat et al. very recently reported the hydroboration of CO
2
and bis(perfluorocatecholato)silane [Si(cat ) ]
1
4c
have been lately
2
2
a
1
4d-e
2
and a silane as the formylation reagent.
2
4f
1
was carried out to understand the mechanism.
using an well-defined guanidine substituted hydrosilane.
Boosted by the success of alanes ( ) and phosphane ( ), we
were interested in exploring the catalytic potential of
previously reported benz-amidinato silane [PhC(NtBu) SiHCl ],
), for hydroboration reaction. Our results are reported
A
-C
G
The addition of a B-H bond to the C=C, C=O, and C=N bonds
1
requires a catalyst. Group 4 metallocenes and precious metal
2
2
1
5a
compounds, especially organometallic rhodium and iridium
2
complexes are the most studied catalysts for hydroboration
(
1
herein.
reactions. Due to the environmental concern, limited
terrestrial abundance, the high cost of traditional transition
metal catalysts, there is a recent surge to explore compounds
with main group elements as feasible alternatives of transition
Ph
t
Bu
Dipp
Mes
Dipp
tBu
Ph
N
E
Ph
N
H
N
N
N
N
H
Si Cl
Cl
H
SiiPr
3
Al
N
Al
Ge
PH
tBu
Ph
iPr
X
N
t
N
NMe Et
2
H
N
N
Dipp
Bu
1
Mes
Dipp
3
-6
Ph
metal catalysts. Encouragingly, a number of research groups
such as Hill, Roesky, Wesemann, Nembenna, Jones, Zhao,
X=H (A)
OSO CF
2 3
(B)
C
E=Ge (D) and Sn (E)
F
G
This Work
7
-13
Kinjo, and others
have started to use compounds with s- Chart 1. Single component compounds with heavier p-block elements that catalyzes
hydroboration of aldehydes (A-G); This work reports the first use of a neutral silicon
and p-block elements as single site catalysts for catalytic
hydroboration of aldehydes and ketones (Scheme 1). However,
when we look at the full gamut of single site neutral
compounds reported for transition metal free hydroboration
of aldehydes and ketones, there is one element missing that
one might have expected to be there: silicon.
(
IV) compound (1) for aldehyde hydroboration.
t
Bu
N
H
Si Cl
Cl
O
R1
O
O
O
O
Ph
Catalyst 1
B
+
H
B
H
N
R1
H
Being an isostere of carbon and owing to the larger
covalent radius, electropositive nature, low toxicity and
relative abundance, silicon compounds are highly sought after
as single component catalysts because a catalytic cycle based
on silicon could be sustainable, economical and green. Silylium
solvent, rt
H
O
t
1
Bu
R = alkyl/aryl
1
Scheme 1. Silicon(IV) hydride (1) catalyzed hydroboration of aldehydes.
Compound
1 was previously reported by Roesky et al. as a
5a
1
precursor for silicon(II) chloride
1
and silicon(II)
5b
bis(trimethylsilyl)amide.
Compound
1
was chosen as a
catalyst for hydroboration reaction because it can be
1
5a
synthesized in a single step with high yield. Direct addition
of HBpin to benzaldehyde in absence of the catalyst only
2
afforded trace amount of PhCH OBpin; an observation also
7,8,11,12
noted by others.
However, when the reaction was
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 1
Please do not adjust margins

Please do not adjust margins
Dalton Transactions
Page 3 of 57
View Article Online
DOI: 10.1039/C6DT04893E
COMMUNICATION
Journal Name
carried out in presence of 1 mol% of
1, it led to the carbonyl carbon of the benzaldehyde. This occurs through a
2
quantitative conversion to PhCH OBpin at room temperature four-membered transition state (TS-1) and leads to the
in an hour (Scheme 2). When the catalyst loading was reduced formation of Int-2 (see Figure 1). The ΔE (-23.9 kcal/mol) and
to 0.5 mol%, the conversion was still achieved albeit with ΔG (-18.4 kcal/mol) values for this step are highly negative and
#
slightly lower yield (77%) (See Supporting Information, Table the activation energy (ΔG ) barrier corresponding to the
S1). Therefore, each reaction was conducted at room transition state is 28.8 kcal/mol, which is moderate and
temperature with 1 mol% catalyst in an equimolar mixture of explains why the reaction can take place at room temperature.
aldehyde and HBpin. We have also performed the reaction in This is also the slowest step of the overall hydroboration
3
presence of only 1 mol% of HSiCl as a catalyst, but only trace reaction. The silicon centre of catalyst 1 therefore acts as the
amount of product formation was observed. We have explored hydride donor to the electrophilic carbonyl carbon centre.
the reactions in various solvents such as benzene, toluene,
dichloroethane and observed that the identity of the solvent
had little effect on the yields. The products were identified by
1
13
a combination of GC-MS, H and C NMR spectroscopies.
In order to understand possible mechanistic pathway,
simple NMR experiments were performed. As silicon is in +4
oxidation state, it is expected that the catalysis will occur via σ-
bond metathesis, which has a modicum of precedence for non-
1
6
metal p-block elements. When a 1:1 mixture of
1
and
1
was monitored by H NMR, the
benzaldehyde in CDCl
3
development of a new singlet at δ 5.05 ppm was observed
with concomitant disappearance of the aldehyde proton (δ
1
5a
13
9
.95 ppm) as well as Si-H proton (δ 6.26 ppm). The C NMR
spectrum was (in CDCl ) also changed, with a new peak
appearing at δ 66.00 ppm for [-OCH -] substituent, which was
3
2
2
9
further confirmed by DEPT experiments. The Si NMR
spectrum showed a new resonance at δ –101.2 ppm, which is
slightly upfield shifted than that in
agreement with the previously reported penta-coordinate
silicon compounds bearing Si–O bond such as
PhC(NtBu) SiCl OR, (R=iPr and tBu)]. Taken together, these
data suggest the possible formation of alkoxy compound
PhC(NtBu) SiCl OCH Ph] (Int-2) as an intermediate. However,
1 (δ –96.6 ppm) but in good
a
1
5c
[
2
2
[
2
2
2
even after repeated attempts, we could not obtain the single
crystals of Int-2. In order to prove the formation of Int-2
during the catalytic cycle, we performed the metathetical Scheme 2. The catalytic cycle and reaction mechanism for the benzaldehyde
1
]
7
hydroboration by catalyst 1, calculated at the PBE/TZVP level of theory with DFT.ΔG
reaction between [PhC(NtBu)
2
SiCl
3
and potassium
#
and ΔG represent the Gibbs free energy of reaction and the Gibbs free energy of
benzyloxide, which also led to Int-2. Comparison of spectra
obtained from two different reactions unequivocally confirms
that Int-2 was being formed during the catalytic cycle. The
formation of a strong Si–O bond can be presumed as the
activation respectively. All values are in kcal/mol.
In the next step, pinacolborane approaches the Si-O bond
of Int-2, which then passes through a Si-O-B-H four membered
cyclic transition state (TS-2), leading to the formation of the
hydroboration product (Pdt-1) along with the regeneration of
the catalyst. The regeneration of the catalyst has also been
1
8
driving force for the metathesis reaction.
Full quantum mechanical calculations were done with
density functional theory (DFT) at the dispersion and solvent
corrected PBE/TZVP level of theory in order to understand the
mechanism (Figure S1 and Scheme 2) of the aldehyde
1
observed in the H NMR spectroscopy from the stoichiometric
reaction between Int-2 and HBpin with the reappearance of
the Si-H resonance at δ 6.26 ppm in the reaction mixture with
concomitant disappearance of the B-H protons. The four-
membered cyclic transition state (TS-2) involves a H-bonding
interaction between the Si and B atoms and in this transition
state there is a significant amount of B-H bond activation takes
place (1.27 Å) in comparison to that in HBpin (1.19 Å). Such
elongation allows the hydride transfer from the boron to the
silicon atom leading to the simultaneous Si-O bond cleavage
and B-O bond formation. Similar mechanistic proposal for the
regeneration of aluminum hydride catalyst was suggested by
hydroboration reaction in the presence of the catalyst
1 [for
further details, please see the Supporting Information]. In the
first step of the reaction, a loosely bound complex (Int-1) is
formed between the catalyst
1 and benzaldehyde, with the
benzaldehyde approaching towards the catalyst from the
direction opposite to the Si–N bond. The reaction energy (ΔE)
and the Gibbs free energy (ΔG) for this step are –6.3 kcal/mol
and 5.6 kcal/mol, respectively. This is the prelude to the
nucleophilic attack by the carbonyl oxygen of benzaldehyde to
the silicon centre of the catalyst, with the hydride being
transferred from the silicon centre to the electrophilic
2
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Ple Da s ae l tdo onn To rt aa nd sj ua s ct t mi o an r sg ins
Page 4 of 57
View Article Online
DOI: 10.1039/C6DT04893E
Journal Name
COMMUNICATION
Zhi, Parameswaran, and Roesky. The driving force of the
Subsequently, the scope of the catalytic reaction was
reaction can be attributed to the oxophilicity of the boron examined with a range of aldehydes. Reactions were
1
atom. The ΔE (-11.4 kcal/mol) and ΔG (-9.6 kcal/mol) values monitored by H NMR spectroscopy with the appearance of
9
1
#
for this step are highly negative and the barrier (ΔG ) is 27.1 new upfield resonances corresponding to the α-protons of the
kcal/mol. To confirm the slowest step, we have employed the boronate ester. Most of the aromatic aldehydes are converted
2
energetic span model (ESM) calculations and have found that to the corresponding boronate esters at room temperature in
0
st nd
the percentage contribution for the 1 and 2 transition short reaction time in good yields (entries 1-15). No inhibitory
states are 95% and 5%. Hence the first step is seen to be the effect was observed for ortho substituents (entries 7 and 9).
slowest step of the overall hydroboration process.
The reaction showed tolerance towards fluoride groups, as
demonstrated by the clean hydroboration of 4-
fluorobenzalhedye (entry 4). When salicylaldehyde or 4-
hydroxybenzaldehyde were used, hydroboration was occurred
at the aldehyde functional group as well as double
hydroboration was occurred in aldehyde and OH groups
[
a]
Table 1. Hydroboration of aldehydes catalyzed by 1.
[
b]
Entry
1
Substrate
Cat (mol%)
-
Time [h]
0.5
Yield [%]
trace
(minor products) (entries 9 and 10). However, only
hydroxylborane dehydrocoupled product has not been
formed. Hydroboration of cinnamaldehyde led to the 1,2-
adducts, keeping the olefinic functionality intact (entry 8). The
reaction of 4-pyridine-carboxaldehyde with HBpin led to
exclusive hydroboration of the carbonyl functionality instead
of pyridine dearomatization (entry 13).
2
3
4
1
1
1
1
1
1
96
90
90
Table 2. Hydroboration of imines Catalyzed by 1 and the conversion of amine
[
a]
boronates to secondary amines.
5
6
7
8
9
1
1
1
1
88
85
Ar1
N
H
N
Ar1
N
Catalyst 1 Ar
silica, methanol Ar
65 °C, 4-6 h
O
Ar1
+ H Bpin
H
B
Ar
6
5 ºC, CH3CN
H
H
O
H
H
1
1
1
82
95
[
b]
Entry
1
Substrate
Cat (mol%)
2
Time [h]
48
Yield [%]
1.5
86
1
1
75
2
3
4
5
2
2
2
2
48
48
50
72
74
87
88
76
1
1
1
0
1
2
1
1
1
1
1
1
72
84
70
N
O2N
1
3
1
1
90
6
7
8
2
2
2
72
72
72
79
88
1
1
4
5
1
1
1
5
52
95
52
[
a]
All reactions carried out in benzene at room temperature using 1 equiv of
[a]
[b]
All reactions carried out in acetonitrile at 65 °C using 1 equiv of HBpin. Yields
are isolated yield of secondary amines.
[b]
HBpin. Conversion was determined by NMR spectroscopy on the basis of the
consumption of the aldehyde and the identity of the product was confirmed by
2
RCH OBpin or resonances.
We further examined the scope of hydroboration for
ketones. However, even after increasing the mol% of the
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
Dalton Transactions
Page 5 of 57
COMMUNICATION
View Article Online
DOI: 10.1039/C6DT04893E
Journal Name
catalyst, reaction temperature, time, changing solvent did not transition state (TS-4), with the barrier being 40.8 kcal/mol.
lead to the hydroboration of ketone. In fact, no reaction was This higher barrier explains why the reaction requires heating
observed between
1
and ketone which can be attributed to to 65 °C.
In summary, we have demonstrated the first use of a well-
the higher coordination and sterics around the silicon atom.
Consistent with that, theoretical calculations also reveal that defined neutral silicon(IV) compound for catalytic
both barriers are substantially higher for ketones than those of hydroboration of aldehydes and aldimines. The initial step in
aldehydes.
The silane catalyzed hydroboration has been extended to C=O bond via a four-membered transition state. The second
imines; which has been scarcely studied. The first transition step involves the σ-bond metathesis between
metal-catalyzed imine hydroboration was reported by Baker [PhC(NtBu) SiCl OCH Ph] (Int-2) and HBpin resulting in the
and Westcott et al. using Au complexes, which were followed product formation along with the regeneration of the catalyst.
the catalytic cycle is the facile addition of the Si–H bond to the
2
2
2
2
1
2
2-25
by few more reports.
hydroboration was reported by the group of Hill using believe that our findings will spur more interest among
magnesium compound [CH{C(Me)NAr} MgnBu] (Ar=2,6- researchers to design many more silicon(IV) compounds as
and the group of Crudden using Lewis adduct of catalysts for various organic transformations.
The transition metal free imine The mechanism was further supported by DFT calculations. We
2
2
6
iPr
DABCO and B(C
hydroboration of imines with slightly harsher condition. Research Board (SERB), India (SB/S1/IC-10/2014). M. K. B. and
Purification of products by SiO column chromatography led T. D. thank CSIR, India for the research fellowships. K. V.
2 6 3
C H )
2
.
7
6
F
5
)
3
It was observed that
1
catalyzes
This work was supported by Science and Engineering
2
exclusively to corresponding secondary amines.
acknowledges “MSM” (CSC0129) and DST (EMR/2014/000013)
for funding. S. S. S. also thanks the Ramanujan research grant
(
SB/S1/RJN-073/2014). We thank Prof. Swadhin K. Mandal
from Indian Institute of Science Education and Research
IISER), Kolkata for providing us trichlorosilane (HSiCl ). We are
(
3
thankful to the reviewers for their critical suggestions to
improve the manuscript.
Notes and references
1
(a) X. He and J. F. Hartwig, J. Am. Chem. Soc., 1996, 118
696–1702; (b) J. F. Hartwig and C. N. Muhoro,
Organometallics, 2000, 19, 30–38.
,
1
2
(a) K. Oshima, T. Ohmura and M. Suginome, J. Am. Chem.
Soc., 2012, 134, 3699–3702; (b) J. Cid, J. J. Carbo and E.
Fernandez, Chem. Eur. J., 2012, 18, 1512–1521; (c) S. M.
Smith and J. M. Takacs, Org. Lett., 2010, 12, 4612–4615; (d)
S. M. Smith and J. M. Takacs, J. Am. Chem. Soc., 2010, 132,
740–1741; (e) C. J. Lata and C. M. Crudden, J. Am. Chem.
1
Soc., 2010, 132, 131–137; (f) B. Nguyen and J. M. Brown,
Adv. Synth. Catal., 2009, 351, 1333–1343 and references
therein.
3
S. Yadav, S. Saha and S. S. Sen, ChemCatChem, 2016,
01.
C. C. Chong and R. Kinjo, ACS Catal., 2015,
For catalysis with alkaline earth metal, please see: (a) T. E.
Stennett and S. Harder, Chem. Soc. Rev., 2016, 45, 1112–
7
, 486–
5
4
5
5, 3238−3259.
1
128; (b) M. S. Hill, D. J. Liptrot and C. Weetman, Chem. Soc.
Rev., 2016, 45, 972-988; (c) S. Harder, Chem. Rev., 2010, 110
852–3876.
(a) Q.-L Zhou, Angew. Chem., Int. Ed., 2016, 55, 5352–5353;
b) S. Bagherzadeh and N. P. Mankad, Chem. Commun., 2016,
, 3844–3846; (c) D. Mukherjee, H. Osseili, T. P. Spaniol and
,
3
Scheme 3. The catalytic cycle and reaction mechanism for the imine hydroboration by
#
6
7
catalyst 1, calculated at the PBE/TZVP level of theory with DFT. ΔG and ΔG represent
(
3
the Gibbs free energy of reaction and the Gibbs free energy of activation respectively.
All values are in kcal/mol.
5
J. Okuda, J. Am. Chem. Soc., 2016, 138, 10790–10793; (d) S.
C. Sau, R. Bhattacharjee, P. K. Vardhanapu, G. Vijaykumar, A.
We have also carried out quantum mechanical calculations
to explore the reaction mechanism at the same level of theory
for the imine hydroboration in the presence of the silane
catalyst (Scheme 3 and Figure S1). The bond making and
breaking between the Si–N and B–H bond are involved in the
transition state (TS-4) with a significant B–H bond activation
Datta and S. K. Mandal, Angew. Chem., Int. Ed., 2016, 55
15147–15151.
,
(a) M. Arrowsmith, T. J. Hadlington, M. S. Hill and G. Kociok-
Köhn, Chem. Commun., 2012, 48 4567−4569; (b) C.
Weetman, M. D. Anker, M. Arrowsmith, M. S. Hill, G. Kociok-
Köhn, D. J. Liptrot and M. F. Mahon, Chem. Sci., 2016,
28–641; (c) C. Weetman, M. S. Hill and M. F. Mahon, Chem.
Commun., 2015, 51, 14477–14480; (d) K. Manna, P. Ji, F. X.
Greene and W. Lin, J. Am. Chem. Soc., 2016, 138, 7488 7491;
,
7,
6
(1.28 Å). The only differences in this case compared to those of
aldehydes are the energy barriers, especially at the second
−
4
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Ple Da s ae l tdo onn To rt aa nd sj ua s ct t mi o an r sg ins
Page 6 of 57
View Article Online
DOI: 10.1039/C6DT04893E
Journal Name
COMMUNICATION
(
5
2
e) D. Mukherjee, A. Ellern and A. D. Sadow, Chem. Sci., 2014, 27 P. Eisenberger, A. M. Bailey and C. M. Crudden, J. Am. Chem.
Soc., 2012, 134, 17384−17387.
, 959–965; (f) L. Fohlmeister and A. Stasch, Chem. Eur. J.,
016, 22, 10235–10246; (g) D. Mukherjee, S. Shirase, T. P.
Spaniol, K. Mashima and J. Okuda, Chem. Commun., 2016,
2, 13155–13158.
5
8
(a) Z. Yang, M. Zhong, X. Ma, S. De, C. Anusha, P.
Parameswaran and H. W. Roesky, Angew. Chem., Int. Ed.,
2
015, 54, 10225–10229; (b) Z. Yang, M. Zhong, X. Ma, K.
Nijesh, S. De, P. Parameswaran and H. W. Roesky, J. Am.
Chem. Soc., 2016, 138, 2548−2551.
9
1
1
1
1
1
J. Schneider, C. P. Sindlinger, S. M. Freitag, H. Schubert and L.
Wesemann, Angew. Chem., Int. Ed., 2017, 56, 333–337.
0 V. K. Jakhar, M. K. Barman and S. Nembenna, Org. Lett.,
2
016, 18, 4710–4713.
1 T. J. Hadlington, M. Hermann, G. Frenking and C. Jones, J.
Am. Chem. Soc., 2014, 136, 3028–3031.
2 Y. Wu, C. Shan, Y. Sun, P. Chen, J. Ying, J. Zhu, L(Leo). Liu and
Y. Zhao, Chem. Commun., 2016, 52, 13799−13802.
3 C.-C. Chong, H. Hirao and R. Kinjo, Angew. Chem., Int. Ed.,
2
015, 54, 190−194.
4 (a) K. Müther, J. Mohr and M. Oestreich, Organometallics,
013, 32, 6643–6646; (b) A. R. Nödling, K. Müther, V. H. G.
Rohde, G. Hilt and M. Oestreich, Organometallics, 2014, 33
02–308; (c) A. L. Liberman-Martin, R. G. Bergman and T. D.
2
,
3
Tilley, J. Am. Chem. Soc., 2015, 137, 5328–5331; (d) L. Hao, Y.
Zhao, B. Yu, Z. Yang, H. Zhang, B. Han, X. Gao and Z. Liu, ACS
Catal., 2015, 5
, 4989−4993; (e) Q. Zhou and Y. Li, J. Am.
Chem. Soc., 2015, 137, 10182–10189; (f) N. von Wolff, G.
Lefèvre, J.-C. Berthet, P. Thuéry and T. Cantat, ACS Catal.,
2016, 6, 4526–4535; (g) K. Müther and M. Oestreich, Chem.
Commun., 2011, 47, 334–336.
1
1
5 (a) S. S. Sen, H. W. Roesky, D. Stern, J. Henn and D. Stalke, J.
Am. Chem. Soc., 2010, 132, 1123-1126; (b) S. S. Sen, J. Hey,
R. Herbst-Irmer, H. W. Roesky and D. Stalke, J. Am. Chem.
Soc., 2011, 133, 12311–12316; (c) C.-W. So, H. W. Roesky, P.
M. Gurubasavaraj, R. B. Oswald, M. T. Gamer, P. G. Jones and
S. Blaurock, J. Am. Chem. Soc., 2007, 129, 12049-12054.
6 (a) Y. Wang, W. Chen, Z. Lu, Z.-H. Li and H. Wang, Angew.
Chem., Int. Ed., 2013, 52, 7496–7499; (b) C.-C. Chong, H.
Hirao and R. Kinjo, Angew. Chem., Int. Ed., 2014, 53, 3342–
3
346; (c) G. I. Nikonov, S. F. Vyboishchikov and O. G.
Shirobokov, J. Am. Chem. Soc., 2012, 134, 5488–5491.
7 C.-W. So, H. W. Roesky, J. Magull and R. B. Oswald, Angew.
Chem., Int. Ed., 2006, 45, 3948–3951.
8 One reviewer suggested that the actual catalyst could be
silylium ion generated from the reaction of 1 with HBpin. So
1
1
far we could not obtain any conclusive NMR spectroscopic
evidence for the formation of silylium ions.
1
2
9 For comparison of oxophilicity, please see: K. S. Kepp, Inorg.
Chem., 2016, 55, 9461–9470.
0 (a) S. Kozuch and S. Shaik, Acc. Chem. Res. 2010, 44
1
,
01−110; (b) S. Kozuch and J. M. L. Martin, ACS Catal. 2011,
, 246−253.
1
2
2
1 R. T. Baker, J. C. Calabrese and S. A. Westcott, J. Organomet.
Chem., 1995, 498, 109 117.
2 L. Koren-Selfridge, H. N. Londino,; J. K. Vellucci, B. J.
−
Simmons, C . P. Casey and T. B. Clark, Organometallics, 2009,
28
, 2085−2090.
2
2
3 A. E. King, S. C. E. Stieber, N. J. Henson, S. A. Kozimor, B. L.
Scott, N. C. Smythe, A. D. Sutton and J. C. Gordon, Eur. J.
Inorg. Chem., 2016, 1635−1640.
4 C. M. Vogels, P. O. O’Connor, T. E. Phillips, K. J. Watson, M. P.
Shaver, P. J. Hayes and S. A. Westcott, Can. J. Chem., 2001,
79
, 1898–1905.
5 A. Kaithal, B. Chatterjee and C. Gunanathan, J. Org. Chem.,
016, 81, 11153–11161.
6 M. Arrowsmith, M. S. Hill and G. Kociok-Köhn, Chem. Eur. J.,
013, 19, 2776 2783.
2
2
2
2
−
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
Please do not adjust margins

Page 7 of 57
Dalton Transactions
View Article Online
DOI: 10.1039/C6DT04893E
Supplementary Information
for
Transition metal free catalytic hydroboration of aldehydes and
aldimines by amidinato silane
[
a]
[a]
[b]
[b]
[a]
Milan Kumar Bisai, Sanjukta Pahar, Tamal Das, Kumar Vanka* and Sakya S. Sen*
Contents:
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
General Experimental Information.
Stoichiometric reaction of catalyst 1 and benzaldehyde
General catalytic procedure for the hydroboration of aldehydes.
Optimization table of hydroboration of benzaldehyde catalysed by 1.
Analytical data of boronate ester and isolated primary alcohol of corresponding
aldehydes.
ꢀ
General catalytic procedure for the hydroboration of Imines to corresponding
secondary amines.
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
Optimization table of hydroboration of diphenyl imines catalysed by 1 in acetonitrile.
Analytical data of secondary amines.
Details of the theoretical calculations.
Representative NMR spectra.
References.
1

Dalton Transactions
Page 8 of 57
View Article Online
DOI: 10.1039/C6DT04893E
General Experimental Information
All reactions were performed under argon atmosphere using Schlenk techniques or inside aM
Braun glove box. Pinacolborane (HBpin), aldehydes were purchased from Sigma–Aldrich,
Alfa–Aesar, and TCI and used without further purification. Imines obtained from
benzaldehyde derivatives were prepared by stirring the carbonyl precursor with 1.1
equivalents of the relevant amine in dichloromethane over molecular sieves for 18 hours at
room temperature, followed by filtration, solvent removal and recrystallization of the imine
[
S1]
[S2]
from hexanes.
distilled from Na/benzophenone and further dried by molecular sieves prior to use.
Acetonitrile was used from MBraunꢀSPS 800. C and CDCl were purchased from Sigmaꢀ
Aldrich, were degassed by three freezeꢀpumpꢀthaw cycles, and stored over molecular sieves.
Compound 1 was synthesized by a literature procedure.
Benzene was
D
6 6
3
1
13
1
H, C{ H}NMR spectra were recorded on Bruker AV–200MHz and referenced to the
resonances of the solvent used.
Stoichiometric reaction of catalyst 1 and benzaldehyde
A solution of Benzaldehyde (0.1 g, 1 mmol) in toluene (5 mL) was added dropwise to the
toluene solution (15 mL) of 1 (0.3 g, 1 mmol) at –60 °C. The reaction mixture was stirred at
room temperature overnight. Volatiles of the mixture were removed under reduced pressure.
The residue was extracted with toluene and concentration of the solution led to colorless solid
1
of Int-2. Yield (0.40 g, 49%), H NMR (CDCl 500 MHz, 298 K): δ 7.80ꢀ7.28 (m, 10H,
3
,
1
3
ArH), 5.05 (s, 2H, OCH
98 K): δ 31.56 (CH ), 55.45 (C(CH
CDCl 500 MHz, 298 K): δ ꢀ101.28 ppm.
2
), 1.17 (s, 18H, CH
3 3
) ppm; C{1H} NMR (CDCl , 125.70 MHz,
2
9
1
2
3
3
)
3
), 66.00 (OCH ), 155.15 (NCN) ppm; Si{ H}NMR
2
(
3
,
Note: The formation of Int-2 was always accompanied with the formation of free amidinate
1
3
ligand! As a result designation of phenyl carbons in Int-2 from the C NMR spectrum was
difficult.
Alternative Preparation of Int-2. To the solution of KOBn (0.2 g, 1.36 mmol) in 10 mL
toluene, toluene solution (20 mL) of PhC(NtBu)
2
SiCl
3
(0.5 g, 1.36 mmol) was added drop by
ο
ο
drop at ꢀ78 C. The reaction mixture was stirred for 30 min at ꢀ78 C and then slowly allowed
to room temperature and stirred overnight. The filtrate was collected by filtration through
celite pad glass frit, concentrated under vacuum and kept for crystallization. Yield: 52%.
General catalytic procedure for the hydroboration of aldehydes
Aldehyde (0.5 mmol), pinacolborane (0.5 mmol), catalyst (1 mol%), benzene (1 mL) were
charged in a Schlenk tube with a magnetic bead inside the glove box. The reaction mixture
1
was allowed to stir at room temperature. The progress of the reaction was monitored by H
2

Page 9 of 57
Dalton Transactions
View Article Online
DOI: 10.1039/C6DT04893E
NMR, which indicated the completion of the reaction by the disappearance of aldehyde
RCHO) proton and appearance of a new OCH resonance. For isolation of corresponding
(
2
primary alcohol of few aldehyde, reactions were scaled up and carried out at same reaction
condition as mentioned.
Upon completion of the reaction, three of the resulted boronate ester residue were hydrolysed
by silica gel with methanol at 60 °C for 4–6 hrs. The completion of hydrolysis was checked
by TLC. Upon completion, the reaction mixture was filtered and washed three times with
dichloromethane. The combined organic layers were dried, evaporated and the residue was
purified by column chromatography over silica gel (100–200 mesh) with pet ether/ethyl
acetate (20:1) mixture as eluent, which provided the pure primary alcohols.
Table S1. Optimization Table of Hydroboration of Benzaldehyde Catalysed by 1 in
benzene
entry
catalyst
temp.
Time
Conv.
(%)
77
(mol%)
(h)
1
1
2
3
4
0.5
rt
0.5
50 °C
rt
1
88
1.0
1
96
1.5
rt
1
96
1
13
Analytical data and NMR ( H, C) spectra of boronate esters of corresponding
aldehydes
1
2
-(benzyloxy)-pinacolborane (2): H NMR (CDCl
3
, 200 MHz, 298 K): δ 7.28ꢀ7.18 (m, 5H,
13
ArH), 4.85 (s, 2H, OCH
2 3 3
), 1.18 (s, 12H, CH ) ppm; C{1H} NMR (CDCl ,
O
B
O
O
50.28 MHz, 298 K): δ 24.48 (CH ), 66.55 (CH ), 82.90 (C(CH ) ), 126.65
3
2
3 2
(Ph), 127.27 (Ph), 128.20 (Ph), 139.16 (ArCꢀR) ppm.
1
2
-((4-methylbenzyl)oxy)-pinacolborane (3): H NMR (CDCl
3
, 200 MHz, 298 K): δ 7.18ꢀ
3
3
7
.14 (d, J =8.0 Hz, 2H, ArH), 7.07ꢀ7.03 (d, JHꢀH=7.9Hz, 2H, ArH), 4.80
HꢀH
O
B
13
O
O
(s, 2H, CH
CDCl , 50.28 MHz, 298 K): δ 21.05 (ArꢀCH
2.80 (C(CH ), 126.77 (Ph), 126.87 (Ph), 136.19 (Ph), 139.90 (Ph) ppm.
), 2.25 (s, 3H, ArCH
), 1.18 (s, 12H, CH
) ppm; C{1H} NMR
2
3
3
(
3
3
), 24.54(CH
3 2
), 66.51(CH ),
8
3 2
)
3

Dalton Transactions
Page 10 of 57
View Article Online
DOI: 10.1039/C6DT04893E
1
2
-((4-fluorobenzyl)oxy)-pinacolborane (4): H NMR (CDCl
3
, 200 MHz, 298 K): δ 7.30ꢀ
13
6
.85 (m, 4H, ArH), 4.80 (s, 2H, CH ), 1.19 (s, 12H, CH ) ppm; C NMR
2
3
O
B
O
O
(CDCl
3 3 2 3 2
, 50.28 MHz, 298 K): δ 24.51 (CH ), 65.98 (CH ), 83.01 (C(CH ) ),
F
115.05 (d, JCꢀF=21.22 Hz, ArꢀC), 128.58 (d, JC–F=8.05 Hz, ArꢀC), 134.88 (Arꢀ
C), 162.13 (d, JCꢀF = 245.17 Hz, ArCꢀF) ppm.
1
2
-((4-bromobenzyl)oxy)-pinacolborane (5): H NMR (CDCl
3
, 200 MHz, 298 K): δ 7.36 (d,
2
H, ArH), 7.12(d, 2H, ArH), 4.78 (s, 2H, CH
2
), 1.18 (s, 12H, CH ) ppm.
3
1
2
3
-((3-bromobenzyl)oxy)-pinacolborane (6): H NMR (CDCl , 200 MHz, 298 K): δ 7.49ꢀ
13
7
.06 (m, 4H, ArH), 4.81 (s, 2H, CH ), 1.19 (s, 12H, CH ) ppm; C NMR
2
3
O
B
Br
O
O
(CDCl
3 3 2 3 2
, 50.28 MHz, 298 K): δ 24.56 (CH ), 65.77 (CH ), 83.12 (C(CH ) ),
1
25.09 (Ph), 129.66 (Ph), 129.81 (Ph), 130.37 (Ph), 137.24 (Ph), 141.45
(Ph) ppm.
1
2
3
-((2-bromobenzyl)oxy)-pinacolborane (7): H NMR (CDCl , 200 MHz, 298 K): δ 7.47ꢀ
1
3
6
.97(m, 4H, ArH), 4.90(s, 2H, CH
2 3
), 1.19 (s, 12H, CH ) ppm; C NMR
O
B
O
O
(CDCl , 50.28 MHz, 298 K): δ 24.53 (CH ), 66.21 (CH ), 83.08 (C(CH ) ),
3
3
2
3 2
Br
121.45 (Ph), 127.27 (Ph), 127.73 (Ph), 128.54 (Ph), 132.18 (Ph),138.25 (Ph)
ppm.
1
2
-(cinnamyloxy)-pinacolborane (8): H NMR (CDCl 200 MHz, 298 K): δ 7.32ꢀ7.09 (m,
3,
3
5
H, ArH), 6.61ꢀ6.49 (d, 1H, JHꢀH=15.7 Hz, 1H ArCH), 6.29ꢀ6.13 (m, 1H,
O
B
3
13
O
O
CHCH), 4.48ꢀ4.45 (d, 2H, JHꢀH=5.3 Hz, CH
2 3
), 1.18 (s, 12H, CH ) ppm; C
NMR (CDCl , 50.28 MHz, 298 K): δ 24.51 (CH ), 65.17 (CH ), 82.87
3
3
2
3 2
(C(CH ) ), 126.34 (Ph), 126.69 (Ph), 127.42 (Ph), 128.43 (ArꢀCH), 130.54
(ArꢀCHCH), 136.76 (ArCꢀR) ppm.
1
2
-(2-hydroxybenzyloxy)-pinacolborane (9): H NMR (CDCl3, 200 MHz, 298 K): δ 7.11ꢀ
3
7
.07 (d, JHꢀH=7.58 Hz, 2H, ArH,), 6.84ꢀ6.79 (m, 2H, ArH), 4.90 (s, 2H, CH
2
),
),
O
B
13
O
O
1
.19 (s, 12H, CH
4.50 (CH
3
) ppm; C NMR (CDCl
3
, 50.28 MHz, 298 K): δ 24.45 (CH
3
OH
6
2
), 83.49 (C(CH
3
)
2
), 116.85 (Ph), 124.11 (Ph), 128.23 (Ph), 129.22
(Ph), 129.49 (Ph), 152.02 (ArCꢀOH) ppm.
1
2
-(4-hydroxybenzyloxy)-pinacolborane (10): H NMR (CDCl 200 MHz, 298 K): δ 7.19ꢀ
3
,
13
6
2 3
.90 (m, 4H, ArH), 4.76 (s, 2H, CH ), 1.18 (s, 12H, CH ) ppm; C NMR
O
B
O
O
HO
4

Page 11 of 57
Dalton Transactions
View Article Online
DOI: 10.1039/C6DT04893E
(CDCl
3 3 2 3 2
, 50.28 MHz, 298 K): δ 24.41 (CH ), 66.55 (CH ), 83.04 (C(CH ) ),
116.08 (Ph), 124.11 (Ph), 128.19 (Ph),132.45 (Ph), 155.59 (ArCꢀOH) ppm.
1
2
-((3-methoxybenzyl)oxy)-pinacolborane (11): H NMR (CDCl3, 200 MHz, 298 K): δ 7.20ꢀ
6
.67 (m, 4H, ArH), 4.83 (s, 2H, CH
2
), 3.71 (s, 3H, OCH
3
), 1.18 (s, 12H, CH
), 55.05 (OCH ),
3 2
) ), 111.74 (Ph), 113.07 (Ph), 118.77 (Ph), 129.20
3
)
O
B
MeO
O
O
13
ppm; C NMR (CDCl
3
, 50.28 MHz, 298 K): δ 24.49 (CH
3
3
66.43 (CH
2
), 82.89 (C(CH
(Ph), 140.73 (Ph), 159.57 (ArCꢀOMe) ppm.
1
2
-((4-methoxybenzyl)oxy)-pinacolborane (12): HNMR (CDCl3, 200 MHz, 298 K): δ 7.22ꢀ
3
3
7
.17 (d, JHꢀH=8.84 Hz, 2H, ArH), 6.80ꢀ6.76 (d, JHꢀH=8.72 Hz, 2H, ArH),
.77 (s, 2H, CH ), 3.70 (s, 3H, OCH ), 1.18 (s, 12H, CH ) ppm.
O
B
O
O
4
2
3
3
MeO
1
4
-(((4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)oxy)methyl)pyridine (13): H NMR
3
(
CDCl3, 200 MHz, 298 K): δ 8.51ꢀ8.48 (d, JHꢀH=6.06 Hz, 2H, ArH), 7.21ꢀ
O
B
3
O
O
7
.18 (d, J =5.81 Hz, 2H, ArH), 4.87 (s, 2H, CH ), 1.19 (s, 12H, CH ) ppm;
HꢀH
2
3
N
1
3
C NMR (CDCl
3
, 50.28 MHz, 298 K): δ 24.48 (CH
3
), 64.86 (CH
2
), 83.21
3 2
(C(CH ) ), 120.79 (Ph), 128.20 (Ph), 149.36 (Ph) ppm.
1
4
-(((4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)oxy)methyl)benzonitrile (14): H NMR
3
(
CDCl3, 200 MHz, 298 K): δ 7.56ꢀ7.52(d, JHꢀH=8.46 Hz, 2H, ArH), 7.38ꢀ
3
7
.33(d, JHꢀH=7.83 Hz, 2H, ArH), 4.89 (s, 2H, CH
2
), 1.19 (s,12H, CH
3
)
ppm.
1
2
-isobutoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (15): H NMR (CDCl3, 200 MHz,
3
2
98 K): δ 3.60 (d, JHꢀH=6.57 Hz, 2H, CH
2
3 2
), 1.81 (sept, 1H, CH(CH ) ) , 1.25
O
B
3
13
(s, 12H, CH ), 0.88 (d, J =6.69 Hz, 6H, CH(CH ) ) ppm; C NMR (CDCl ,
O
O
3
HꢀH
3 2
3
5
0.28 MHz, 298 K): δ 82.42 (C(CH
3
)
2
),, 71.21 (CH
2
), 29.68 (CH(CH
3
2
) , 24.43
(CH
3
), 18.61 (CH ) ppm.
3
Isolation of primary alcohols
In three cases, we have performed the hydrolysis and isolated the primary alcohols:
1
4
-bromo benzyl alcohol (5'): Yield: 146.5 mg (78.3%); H NMR (CDCl 200 MHz, 298 K):
3
,
3
3
Br
δ 7.42ꢀ7.37 (d, JHꢀH=8.46 Hz, 2H, ArH), 7.17ꢀ7.13 (d, J=7.83 Hz, 2H, ArH),
OH
13
4
.55 (s, 2H, CH
2 3
), 1.61 (s, 1H, OH) ppm; C NMR (CDCl , 50.28 MHz, 298
K): δ 64.58 (CH ), 128.32 (Ph), 128.57 (Ph), 139.74 (Ph) ppm.
2
5

Dalton Transactions
Page 12 of 57
View Article Online
DOI: 10.1039/C6DT04893E
1
(
Pyridine-4-yl)methanol (13'): Yield: 89.5 mg (83%); H NMR (CDCl3, 200 MHz, 298 K):
3
3
δ 8.48ꢀ8.45 (d, J =5.94 Hz, 2H, ArH), 7.31ꢀ7.28 (d, JHꢀH=6.06 Hz, 2H, ArH),
N
HꢀH
OH
13
4
2 3
.74 (s, 2H, CH ), 3.99 (s, 1H, OH) ppm; C NMR (CDCl , 50.28 MHz, 298 K):
δ 62.97 (CH
2
), 121.20(Ph), 149.27(Ph), 151.02 (Ph) ppm.
1
4
-cyano benzylalcohol (14'): Yield: 53 mg (40%); H NMR (CDCl3, 200 MHz, 298 K): δ
3
3
NC
7.67ꢀ7.63 (d, JHꢀH=8.34 Hz, 2H, ArH), 7.50ꢀ7.46 (d, JHꢀH=8.59 Hz, 2H,
1
3
OH
ArH), 4.79 (s, 2H, CH
MHz, 298 K): δ 24.7 (CH
26.98 (Ph), 132.28 (Ph), 146.19 (ArCꢀCN) ppm.
2
), 2.05 (s, 1H, OH) ppm; C NMR (CDCl
3
, 50.28
3
), 64.17 (CH ), 111.11 (CꢀCN), 118.83 (CN),
2
1
General catalytic procedure for the hydroboration of Imines
Imine (1 mmol), pinacolborane (1 mmol), catalyst 1( 2 mol %), acetonitrile (1 mL) were
charged in a Schlenk tube with a magnetic bead inside the glove box. The reaction mixture
o
was allowed to stir at room temperature and then slowly heated at 65 C for 48ꢀ72 h. The
1
progress of the reaction was monitored by H NMR, which indicated the completion of the
reaction by the disappearance of Imine (RCHNR´) proton and appearance of a new CH
2
resonance. Upon completion of the reaction, resulted boronate ester residues were hydrolysed
with silica gel and methanol at 65 °C for 4ꢀ6 h. The completion of hydrolysis was checked by
TLC. Upon completion, the reaction mixture was filtered and washed three times with
dichloromethane. The combined organic layers were dried, evaporated and the residue was
purified by column chromatography over silica gel (100–200 mesh) with pet ether/ethyl
acetate (1:5) mixture as eluent, which provided the pure secondary amines.
Table S2. Optimization Table of Hydroboration of diphenyl imines Catalysed by 1 in
acetonitrile
entry
catalyst
temp.
Time
(h)
24
24
24
Conv.
(%)
0
Trace
70
(mol%)
1
2
3
4
1
2
2
2
rt
rt
65 C
o
o
65 C
48
95
Isolation of secondary amines
N-benzylaniline (16): Isolated Yield: 157.5 mg (86%); H NMR (CDCl3, 200 MHz, 298 K):
δ 7.36ꢀ7.13 (m, 7H, ArH), 6.74ꢀ6.61 (m, 3H, ArH), 4.32 (s, 2H, CH ), 4.01 (s,
1H, NH) ppm; C{1H} NMR (CDCl , 50.28 MHz, 298 K): δ 148.11, 139.40,
1
2
13
N
H
3
6

Page 13 of 57
Dalton Transactions
View Article Online
DOI: 10.1039/C6DT04893E
2
129.23, 128.60, 127.48, 127.19, 117.53, 112.81 (Ph), 48.29 (CH ) ppm.
1
N-(4-methylbenzyl)aniline (17): Isolated Yield: 146 mg (74%); H NMR (CDCl3, 200 MHz,
2
2
98 K): δ 7.20ꢀ7.05 (m, 6H, ArH), 6.67ꢀ6.53 (m, 3H, ArH), 4.20 (s, 2H, CH ),
N
13
H
3
.89 (s, 1H, NH), 2.26 (s, 3H, CH
3
) ppm; C{1H} NMR (CDCl
3
, 50.28 MHz,
298 K): δ 148.19, 136.84, 136.33, 129.27, 129.22, 127.49, 117.45, 112.80
(
Ph), 48.05 (CH ), 21.07 (CH ) ppm.
2
3
1
N-(4-nitrobenzyl)aniline (18): Isolated Yield: 198.5 mg (87%); H NMR (CDCl3, 200 MHz,
3
3
2
98 K): δ 8.20ꢀ8.16 (d, JHꢀH =8.84 Hz, 2H, ArH), 7.55ꢀ7.51 (d, JHꢀH =8.84
N
H
3
Hz, 2H, ArH), 7.22ꢀ7.12 (m, 2H, ArH), 6.78ꢀ6.71 (t, JHꢀH =7.0 Hz,1H,
2
O N
3
ArH), 6.60ꢀ6.56 (d, J
=7.58 Hz, 2H, ArH), 4.47 (s, 2H, CH ), 4.25 (s, 1H,
2
HꢀH
13
1
NH) ppm; C{ H} NMR (CDCl
3
, 50.28 MHz, 298 K): δ 147.47, 147.29,
147.15, 129.35, 127.66, 123.85, 118.18, 112.88 (Ph), 47.58 (CH
2
) ppm.
1
N-benzyl-4-ethylaniline (19): Isolated Yield: 186 mg (88%); H NMR (CDCl 200 MHz,
3,
3
2
6
98 K): δ 7.31ꢀ7.11 (m, 5H, ArH), 6.95ꢀ6.90 (d, JHꢀH =8.46 Hz, 2H,ArH),
N
H
3
.51ꢀ6.47 (d, JHꢀH =6.46 Hz, 2H, ArH), 4.21 (s, 2H, CH
2
), 3.81 (s, 1H,NH),
3
3
2
3
1
.51ꢀ2.39 (q, J
=22.74 Hz, 2H, CH CH ),1.14ꢀ1.06 (t, J
=15.16 Hz,
HꢀH
HꢀH
2
3
13
2
H, CH CH
3
) ppm; C{1H} NMR (CDCl
3
, 50.28 MHz, 298 K): δ 146.06,
39.61, 133.43, 128.55, 127.51, 127.13, 112.98 (Ph), 48.65 (CH
2
NH), 27.90
(
CH CH ), 15.92 (CH CH ) ppm.
2 3 2 3
1
N-(4-fluorobenzyl)aniline (20): Isolated Yield: 152.9 mg (76%); H NMR (CDCl3, 200
MHz, 298 K): δ 7.28ꢀ7.21 (m, 2H, ArH), 7.15ꢀ7.05 (m, 2H, ArH), 6.98ꢀ6.89
N
H
(m, 2H, ArH), 6.68ꢀ6.51 (m, 3H, ArH), 4.21 (s, 2H, CH
2
), 3.92 (s, 1H, NH)
, 50.28 MHz, 298 K): δ 162.01 (d, JCꢀF=245.17
Hz, ArCꢀF), 147.90 (Ph), 135.10 (Ph), 129.25 (Ph), 128.96 (d, JCꢀF=8.05 Hz,
F
13
ppm; C{1H} NMR (CDCl
3
2
Ph), 117.71, (Ph), 115.40 (d, JCꢀF=21.22 Hz, ArꢀC), 112.85 (Ph), 47.57 (CH )
ppm.
1
N-benzyl-4-fluoroaniline (21): Isolated Yield: 158.9 mg (79%); H NMR (CDCl3, 200 MHz,
F
298 K): δ 7.36ꢀ7.23 (m, 5H, ArH), 6.91ꢀ6.82 (m, 2H, ArH), 6.58ꢀ6.51 (m,
N
H
13
2H, ArH), 4.27 (s, 2H, CH
2
), 3.92 (s, 1H, NH) ppm; C{1H} NMR (CDCl
3
,
7

Dalton Transactions
Page 14 of 57
View Article Online
DOI: 10.1039/C6DT04893E
5
1
0.28 MHz, 298 K): δ 155.85 (d, JCꢀF=234.92 Hz, ArCꢀF), 144.44 (Ph),
39.21 (Ph), 128.63 (Ph), 127.45 (Ph), 127.27 (Ph), 115.62 (d, J =22.32
CꢀF
2
Hz, Ph), 113.61 (d, JC–F=7.32 Hz, Ph), 48.89 (CH ) ppm.
1
4
-((phenylamino)methyl)benzonitrile (22): H NMR (CDCl3, 200 MHz, 298 K): δ 7.55ꢀ
3
3
7
.51 (d, JHꢀH =8.46 Hz, 2H, ArH), 7.41ꢀ7.37 (d, JHꢀH =8.08 Hz, 2H, ArH),
N
H
3
3
7
.17ꢀ7.05 (q, JHꢀH =6.46 Hz, 2H, ArH), 6.69ꢀ6.62 (t, JHꢀH =14.65 Hz,
NC
3
1
1
1
H, ArH), 6.52ꢀ6.47 (d, JHꢀH =7.71 Hz, 2H, ArH), 4.34 (s, 2H, CH
2
), 4.14 (s,
, 50.28 MHz, 298 K): δ 147.35, 145.35,
32.37, 129.30, 127.64, 118.83, 118.03, 112.82, 110.83 (Ph), 47.71 (CH
1
3
H, NH) ppm; C{1H} NMR (CDCl
3
2
)
ppm.
1
N-(4-fluorobenzyl)-2,4,6-trimethylaniline (23): Isolated Yield: 126.5 mg (52%); H NMR
CDCl3, 200 MHz, 298 K): δ 7.29ꢀ7.18 (m, 2H, ArH), 6.99ꢀ6.90 (m, 2H, ArH),
6.76 (s, 2H, CH ), 3.94 (s, 2H, NH), 2.95 (s, 1H, CH ) ppm.
(
N
H
2
3
F
Details of the theoretical calculations
All the calculations in this study have been performed with density functional theory (DFT),
[
S3]
[S4]
with the aid of the Turbomole 6.4 suite of programs,
using the PBE functional.
The
[
S5]
[S6]
TZVP
basis set has been employed. The resolution of identity (RI),
along with the
[
S7]
multiple accelerated resolution of identity (marij) approximations have been employed for
an accurate and efficient treatment of the electronic Coulomb term in the DFT calculations.
Dispersion correction (disp3) and solvent correction were incorporated with optimization
[
S8]
calculations using the COSMO model, with dichloroethane (ε = 10.36) as the solvent. The
values reported are ꢁG values, with zero point energy corrections, internal energy and
entropic contributions included through frequency calculations on the optimized minima with
the temperature taken to be 298.15 K. Harmonic frequency calculations were performed for
all stationary points to confirm them as a local minima or transition state structures. The
efficiency of a catalytic cycle, as well as the relative prominence of transition states, can be
estimated using the AUTOF program, which is based on the energetic span model (ESM)
[
S9ꢀS11]
defined by Shaik and coꢀworkers.
According to this model, the TOFꢀdetermining
transition state (TDTS) and intermediate (TDI) can be located from a catalytic cycle by the
8

Page 15 of 57
Dalton Transactions
View Article Online
DOI: 10.1039/C6DT04893E
56
evaluation of the degree of TOF control (XTOF). TOF can be calculated by the following
equation:
KBT
−δ E
RT
TOF =
e
h
Were δE, the energetic span, can be defined as,
δ E = TTDTS −TTDI
If TDTS appears after TDI
δ E = TTDTS −TTDI + ꢀGr
If TDTS appears before TDI
Scheme S1. The reaction energy profile diagram for the catalytic hydroboration of benzaldehyde by
catalyst 1. The values (in kcal/mol) have been calculated at the PBE/TZVP level of theory with DFT.
9

Dalton Transactions
Page 16 of 57
View Article Online
DOI: 10.1039/C6DT04893E
Figure S1.The reaction energy profile diagram for the catalytic imine hydroboration by catalyst 1.
The values (in kcal/mol ) have been calculated at the PBE/TZVP level of theory with DFT.
PBE/TZVP optimized geometries for all the compounds and transition states
1
PBE/TZVP Energy : ꢀ1195016.22 kcal/mol
Si 8.313878 2.355217 10.541270
Cl 9.678086 0.609181 10.836864
N
C
C
N
C
C
C
C
C
C
C
C
C
C
C
C
C
H
H
H
H
7.035584 3.852221 10.650120
5.976721 4.430128 9.786181
5.927036 3.578702 8.504227
8.234040 3.023985 12.260302
9.108244 2.930570 13.476744
10.572745 3.098504 13.026721
7.232577 3.911243 11.954918
6.431431 4.693817 12.928371
5.515114 4.021819 13.752427
4.706960 4.746708 14.629605
4.820180 6.139968 14.699853
5.744157 6.807778 13.889179
6.545956 6.088731 12.999581
8.880443 1.562662 14.141720
8.827704 4.032863 14.510817
4.582487 4.409986 10.437445
6.377870 5.869681 9.412555
5.429582 2.935154 13.694127
7.274389 6.608154 12.375450
3.987821 4.221980 15.261016
7.836649 1.473364 14.477915
1
0

Page 17 of 57
Dalton Transactions
View Article Online
DOI: 10.1039/C6DT04893E
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
9.535969 1.461154 15.018801
9.098180 0.741778 13.447874
5.841619 7.893331 13.947527
4.189722 6.705115 15.388774
4.332268 3.399977 10.793028
3.836994 4.703182 9.684065
4.502501 5.106829 11.280145
6.379933 6.520754 10.296733
5.660767 6.280767 8.686656
7.380108 5.884128 8.961784
8.935710 5.037851 14.080951
9.575386 3.926912 15.309736
7.835574 3.949079 14.968787
10.873087 2.326379 12.310178
11.233095 3.028390 13.903207
10.717199 4.086138 12.564117
6.911255 3.533793 8.017826
5.216750 4.031605 7.798673
5.590992 2.554167 8.716828
7.260407 1.450395 10.001925
Cl 9.597032 3.346262 9.157777
Int-1
PBE/TZVP Energy : ꢀ1411681.79 kcal/mol
Cl 9.233732 0.279024 10.626981
Si 8.308831 2.297104 10.366138
N
N
C
C
H
C
C
H
C
C
C
H
C
H
H
H
C
H
C
H
C
H
H
H
C
H
H
7.160807 3.912183 10.370761
7.355878 2.414712 11.936119
5.385981 3.990120 12.151143
4.252952 3.160869 12.117542
4.309598 2.192871 11.616898
6.632989 3.502426 11.511684
5.316586 5.246287 12.768333
6.204322 5.878183 12.818839
7.532687 1.871871 13.327520
6.616376 4.827380 9.331538
3.057484 3.593653 12.691937
2.174876 2.952297 12.654391
6.979120 0.440947 13.380187
5.901060 0.437642 13.166636
7.134118 0.016023 14.383290
7.478805 ꢀ0.203136 12.647728
4.120405 5.668842 13.352901
4.073169 6.643549 13.842142
2.989992 4.845481 13.314728
2.055880 5.179217 13.770497
5.146265 4.523016 8.995906
5.013706 3.458488 8.756318
4.845596 5.120335 8.122314
4.475065 4.778286 9.825608
6.776042 6.284996 9.799335
6.125157 6.504460 10.654837
6.500342 6.965782 8.980618
1
1

Dalton Transactions
Page 18 of 57
View Article Online
DOI: 10.1039/C6DT04893E
H
C
H
H
H
C
H
H
H
C
H
H
H
H
C
C
C
C
C
C
H
H
H
H
H
C
H
O
7.817765 6.487935 10.086429
6.824422 2.723930 14.392687
7.150936 3.772396 14.359722
7.100710 2.316714 15.375495
5.732259 2.690406 14.311272
9.037019 1.894901 13.661022
9.619699 1.272273 12.972878
9.187758 1.510088 14.679998
9.423557 2.923910 13.619909
7.469606 4.624688 8.066547
8.534073 4.798192 8.275494
7.146613 5.338652 7.296467
7.351600 3.611374 7.657729
7.693587 1.848961 9.085569
3.795671 ꢀ0.833669 11.385999
4.956273 ꢀ0.938375 10.595737
5.882756 ꢀ1.966860 10.840864
5.658581 ꢀ2.877504 11.874560
4.505690 ꢀ2.765349 12.660484
3.572458 ꢀ1.745687 12.413958
3.080019 ꢀ0.035933 11.175598
6.786611 ꢀ2.031672 10.230293
6.381490 ꢀ3.670706 12.072527
4.329465 ꢀ3.476456 13.470036
2.673838 ꢀ1.669569 13.028925
5.238003 0.029079 9.521746
6.163521 ꢀ0.181841 8.934598
4.547717 1.012112 9.260576
Cl 10.148926 3.355948 10.246964
TS-1
PBE/TZVP Energy : ꢀ1411661.75 kcal/mol
C
C
C
C
C
C
C
O
7.681667 ꢀ3.066554 9.702787
7.630406 ꢀ1.779453 10.232665
6.776871 ꢀ0.820864 9.652432
5.984660 ꢀ1.161198 8.537334
6.044302 ꢀ2.448431 8.009651
6.892886 ꢀ3.400052 8.592808
6.693682 0.527104 10.200551
7.225068 0.831596 11.358761
Si 8.249559 2.266885 10.579298
Cl 9.966702 0.881176 10.618299
N
C
C
N
C
C
C
C
C
C
C
C
6.757416 3.452851 10.762236
5.807788 4.164119 9.853288
5.937960 3.556755 8.445419
8.332309 3.177317 12.245320
9.109934 2.982593 13.501936
10.589674 3.242617 13.162681
7.185682 3.824805 11.982775
6.470231 4.763811 12.886940
5.355162 4.300727 13.600116
4.680486 5.157450 14.473062
5.108039 6.480460 14.627183
6.215155 6.945098 13.908578
1
2

Page 19 of 57
Dalton Transactions
View Article Online
DOI: 10.1039/C6DT04893E
C
C
C
C
C
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
6.899377 6.088974 13.043590
8.905117 1.534515 13.986630
8.716600 3.932557 14.642770
4.360358 3.972125 10.339144
6.147054 5.662850 9.748387
5.027869 3.266276 13.479677
7.768627 6.446936 12.488858
3.818753 4.789480 15.033076
7.846973 1.358059 14.228779
9.504861 1.364108 14.892784
9.209018 0.808870 13.223210
6.550542 7.977337 14.024278
4.578304 7.149784 15.307837
4.126576 2.903327 10.452989
3.665103 4.401710 9.602841
4.187831 4.469810 11.301612
5.955683 6.191295 10.689472
5.521715 6.125343 8.970834
7.202667 5.794578 9.473241
8.859518 4.986139 14.371886
9.375872 3.711310 15.494359
7.680421 3.791416 14.974000
10.944612 2.573606 12.370157
11.205959 3.079549 14.058663
10.725047 4.281380 12.828592
6.967670 3.628518 8.071944
5.281915 4.112927 7.761658
5.621706 2.505190 8.414135
7.706133 1.500637 9.267027
8.239463 ꢀ1.491417 11.089726
5.324116 ꢀ0.411747 8.093745
5.431398 ꢀ2.716396 7.147492
6.938419 ꢀ4.409558 8.179240
8.337423 ꢀ3.815630 10.149843
5.858876 1.144575 9.825035
Cl 9.415980 3.765097 9.393201
Int-2
PBE/TZVP Energy : ꢀ1411705.73 kcal/mol
C
C
C
C
C
C
C
O
0.454475 ꢀ4.104541 2.398250
0.505991 ꢀ3.562283 1.112061
ꢀ0.587585 ꢀ3.685724 0.239529
ꢀ1.732198 ꢀ4.364793 0.678844
ꢀ1.786541 ꢀ4.913831 1.965503
ꢀ0.693514 ꢀ4.783161 2.828334
ꢀ0.532223 ꢀ3.075472 ꢀ1.139508
ꢀ0.660113 ꢀ1.646093 ꢀ1.054199
Si 0.347821 ꢀ0.364697 ꢀ1.431879
Cl 2.167917 ꢀ1.561546 ꢀ1.866332
N
C
C
N
C
ꢀ1.003084 0.892559 ꢀ0.860644
ꢀ2.430427 1.193708 ꢀ1.152524
ꢀ2.954563 0.109808 ꢀ2.110264
1.038728 0.796771 ꢀ0.137727
2.364604 1.028101 0.520737
1
3

Dalton Transactions
Page 20 of 57
View Article Online
DOI: 10.1039/C6DT04893E
C
C
C
C
C
C
C
C
C
C
C
C
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
3.379396 1.452694 ꢀ0.556459
ꢀ0.131776 1.497438 ꢀ0.069052
ꢀ0.373955 2.753108 0.689547
ꢀ0.888849 2.725121 1.992400
ꢀ1.111665 3.921546 2.678088
ꢀ0.822596 5.146364 2.067075
ꢀ0.310485 5.174306 0.765132
ꢀ0.086039 3.981203 0.075122
2.791931 ꢀ0.280211 1.214016
2.336451 2.114296 1.608674
ꢀ3.266121 1.138958 0.139703
ꢀ2.572008 2.566789 ꢀ1.834676
ꢀ1.105581 1.768874 2.472069
0.317613 3.999396 ꢀ0.939038
ꢀ1.511249 3.895445 3.693391
2.052729 ꢀ0.560934 1.978685
3.762745 ꢀ0.130741 1.708701
2.895246 ꢀ1.106106 0.502835
ꢀ0.083530 6.127270 0.283858
ꢀ0.996596 6.079987 2.605305
ꢀ3.105450 0.182714 0.658143
ꢀ4.333107 1.222210 ꢀ0.113966
ꢀ3.016253 1.959536 0.822881
ꢀ2.295624 3.386968 ꢀ1.160627
ꢀ3.618215 2.715836 ꢀ2.140067
ꢀ1.937229 2.614908 ꢀ2.730617
2.113081 3.111865 1.214005
3.340321 2.148080 2.055223
1.621641 1.880486 2.407793
3.467691 0.696827 ꢀ1.345907
4.369937 1.594397 ꢀ0.099685
3.069598 2.404246 ꢀ1.013607
ꢀ2.392012 0.104663 ꢀ3.052846
ꢀ4.008614 0.321708 ꢀ2.338472
ꢀ2.880576 ꢀ0.884290 ꢀ1.653181
0.404645 ꢀ3.351530 ꢀ1.645661
1.402744 ꢀ3.038096 0.774448
ꢀ2.589073 ꢀ4.464096 0.007354
ꢀ2.683637 ꢀ5.442705 2.294425
ꢀ0.733928 ꢀ5.209444 3.832871
1.312570 ꢀ4.004226 3.066365
ꢀ1.376867 ꢀ3.434737 ꢀ1.747745
Cl 0.357823 0.470448 ꢀ3.420887
TS-2
PBE/TZVP Energy : ꢀ1669905.89 kcal/mol
C
C
C
C
C
C
C
N
ꢀ1.964443 1.180150 1.607956
ꢀ0.991498 1.683044 0.732869
ꢀ0.759414 3.063168 0.660431
ꢀ1.495503 3.935293 1.463277
ꢀ2.467634 3.435122 2.337798
ꢀ2.700986 2.057957 2.407383
ꢀ0.242898 0.711119 ꢀ0.109249
0.858861 0.008993 0.259215
1
4

Page 21 of 57
Dalton Transactions
View Article Online
DOI: 10.1039/C6DT04893E
C
C
1.882850 0.275648 1.318293
3.200408 0.675358 0.626702
Si 0.801422 ꢀ1.016568 ꢀ1.322966
Cl 2.458281 ꢀ2.433524 ꢀ1.004311
O
B
O
C
C
C
C
C
C
C
C
C
O
C
C
C
N
C
C
ꢀ0.471674 ꢀ2.345195 ꢀ0.633619
ꢀ0.529674 ꢀ3.147229 ꢀ2.298916
ꢀ1.810409 ꢀ3.160479 ꢀ2.802834
ꢀ1.832554 ꢀ4.313970 ꢀ3.731361
ꢀ3.235879 ꢀ4.898543 ꢀ3.722190
ꢀ0.498260 ꢀ3.106475 0.584514
ꢀ1.728317 ꢀ2.775823 1.397126
ꢀ2.994026 ꢀ2.779096 0.789786
ꢀ4.134770 ꢀ2.444793 1.521937
ꢀ4.027518 ꢀ2.111040 2.878348
ꢀ2.773698 ꢀ2.121957 3.496288
ꢀ1.631262 ꢀ2.451110 2.756964
0.224958 ꢀ4.270317 ꢀ2.521971
ꢀ0.724387 ꢀ5.250094 ꢀ3.114422
ꢀ1.240132 ꢀ6.113782 ꢀ1.964454
0.034311 ꢀ6.091621 ꢀ4.126981
ꢀ0.616555 0.291935 ꢀ1.316020
ꢀ1.802324 0.642272 ꢀ2.144811
ꢀ1.494369 0.216602 ꢀ3.592242
Cl 2.000674 0.205945 ꢀ2.718724
C
C
C
C
C
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
ꢀ3.047851 ꢀ0.108500 ꢀ1.643911
ꢀ2.070997 2.158350 ꢀ2.154642
2.086085 ꢀ0.999033 2.155088
1.496725 1.402071 2.289689
ꢀ1.471634 ꢀ3.782127 ꢀ5.118280
ꢀ2.135262 0.103737 1.668611
ꢀ0.004424 3.452549 ꢀ0.024930
ꢀ3.457005 1.661491 3.088245
1.163995 ꢀ1.245894 2.699903
2.882181 ꢀ0.827713 2.893773
2.376397 ꢀ1.851357 1.530133
ꢀ1.310658 5.009593 1.405616
ꢀ3.042795 4.119574 2.964425
ꢀ2.887901 ꢀ1.191444 ꢀ1.692306
ꢀ3.910368 0.147937 ꢀ2.277566
ꢀ3.285184 0.168586 ꢀ0.607835
ꢀ2.471348 2.520049 ꢀ1.201412
ꢀ2.815380 2.373890 ꢀ2.934562
ꢀ1.153976 2.717886 ꢀ2.389818
1.429575 2.377465 1.794130
2.290930 1.465746 3.047153
0.549910 1.202888 2.807930
3.560652 ꢀ0.118200 ꢀ0.038945
3.970241 0.868654 1.388352
3.058789 1.588251 0.031089
ꢀ0.586361 0.711205 ꢀ3.961844
ꢀ2.339404 0.505048 ꢀ4.233592
ꢀ1.371001 ꢀ0.869116 ꢀ3.677096
0.414844 ꢀ2.905756 1.160784
ꢀ0.652777 ꢀ2.446519 3.243148
ꢀ3.075098 ꢀ3.022706 ꢀ0.271978
1
5

Dalton Transactions
Page 22 of 57
View Article Online
DOI: 10.1039/C6DT04893E
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
ꢀ5.111702 ꢀ2.440593 1.033559
ꢀ4.918626 ꢀ1.842684 3.449346
ꢀ2.680259 ꢀ1.860618 4.552366
ꢀ0.484090 ꢀ4.176463 0.316687
0.195718 ꢀ1.843652 ꢀ2.534203
ꢀ0.455462 ꢀ3.362795 ꢀ5.137920
ꢀ1.537838 ꢀ4.575330 ꢀ5.875780
ꢀ2.179603 ꢀ2.986808 ꢀ5.388431
ꢀ0.655514 ꢀ6.770426 ꢀ4.649585
0.543779 ꢀ5.467150 ꢀ4.870692
0.787454 ꢀ6.702259 ꢀ3.610035
ꢀ3.939456 ꢀ4.174792 ꢀ4.156370
ꢀ3.270289 ꢀ5.815695 ꢀ4.327457
ꢀ0.383782 ꢀ6.565699 ꢀ1.445875
ꢀ3.567583 ꢀ5.136066 ꢀ2.704030
ꢀ1.886099 ꢀ6.921490 ꢀ2.335648
ꢀ1.812505 ꢀ5.519579 ꢀ1.237620
Pdt-1
PBE/TZVP Energy : ꢀ1669933.62 kcal/mol
C
C
C
C
C
C
C
N
C
C
ꢀ1.217915 3.314643 ꢀ0.156591
0.010036 3.195638 ꢀ0.825829
0.496472 4.264658 ꢀ1.592600
ꢀ0.236690 5.449571 ꢀ1.680912
ꢀ1.464497 5.566135 ꢀ1.019683
ꢀ1.954570 4.495961 ꢀ0.263247
0.783065 1.933668 ꢀ0.711915
1.376087 1.466335 0.431438
1.868798 2.210282 1.638515
3.366501 1.894963 1.817067
Si 1.672587 ꢀ0.208738 ꢀ0.282184
Cl 2.231845 ꢀ1.341594 1.565918
O
B
O
C
C
C
C
C
C
C
C
C
O
C
C
C
N
C
C
ꢀ1.915508 ꢀ1.670395 0.245034
ꢀ1.335421 ꢀ2.903660 0.092219
ꢀ1.188551 ꢀ3.461588 ꢀ1.166103
ꢀ0.335194 ꢀ4.648857 ꢀ0.984130
ꢀ0.791854 ꢀ5.724195 ꢀ1.959949
ꢀ1.980119 ꢀ1.095589 1.557875
ꢀ2.833652 0.149339 1.555337
ꢀ3.684340 0.464045 0.488069
ꢀ4.480970 1.614176 0.532596
ꢀ4.437892 2.460865 1.644306
ꢀ3.587551 2.152880 2.713475
ꢀ2.791364 1.005611 2.667665
ꢀ0.870055 ꢀ3.689415 1.129220
ꢀ0.560366 ꢀ5.003145 0.539230
ꢀ1.783508 ꢀ5.890867 0.775560
0.662688 ꢀ5.569356 1.246812
0.936895 1.007327 ꢀ1.646819
0.154550 0.771637 ꢀ2.892323
0.652944 ꢀ0.560553 ꢀ3.478965
Cl 3.521849 ꢀ0.537145 ꢀ1.275869
C
C
ꢀ1.347069 0.651411 ꢀ2.576207
0.406758 1.884641 ꢀ3.922905
1
6

Page 23 of 57
Dalton Transactions
View Article Online
DOI: 10.1039/C6DT04893E
C
C
C
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
1.053241 1.753599 2.858972
1.743987 3.735869 1.499387
1.101438 ꢀ4.221903 ꢀ1.290620
ꢀ1.599472 2.482649 0.437796
1.458377 4.175258 ꢀ2.100276
ꢀ2.913244 4.576287 0.251145
ꢀ0.008256 2.004895 2.719969
1.414897 2.263771 3.763835
1.141172 0.670556 3.011214
0.152243 6.283158 ꢀ2.268463
ꢀ2.039033 6.491466 ꢀ1.093321
ꢀ1.522278 ꢀ0.123068 ꢀ1.815956
ꢀ1.894925 0.373516 ꢀ3.489116
ꢀ1.758781 1.600614 ꢀ2.208139
ꢀ0.029446 2.839851 ꢀ3.606413
ꢀ0.054912 1.601664 ꢀ4.880433
1.485178 2.024784 ꢀ4.086053
2.264519 4.110030 0.607174
2.223101 4.185099 2.380690
0.703763 4.079426 1.472067
3.546267 0.823661 1.960011
3.746159 2.426616 2.701638
3.935065 2.235529 0.939101
1.732011 ꢀ0.523793 ꢀ3.681020
0.126894 ꢀ0.758848 ꢀ4.423338
0.448426 ꢀ1.399385 ꢀ2.799047
ꢀ0.960365 ꢀ0.850115 1.902534
ꢀ2.127752 0.772152 3.504392
ꢀ3.711410 ꢀ0.190607 ꢀ0.383166
ꢀ5.133606 1.851610 ꢀ0.310259
ꢀ5.058136 3.358857 1.677315
ꢀ3.539068 2.811436 3.583065
ꢀ2.393655 ꢀ1.831118 2.269702
0.576235 ꢀ1.179574 ꢀ0.534028
1.453713 ꢀ3.459263 ꢀ0.582284
1.786952 ꢀ5.079669 ꢀ1.249450
1.139681 ꢀ3.798452 ꢀ2.303908
0.984069 ꢀ6.506328 0.769282
1.498207 ꢀ4.858857 1.231462
0.413558 ꢀ5.788677 2.294719
ꢀ0.598691 ꢀ5.392390 ꢀ2.989875
ꢀ0.232951 ꢀ6.656344 ꢀ1.792452
ꢀ1.990264 ꢀ5.931405 1.853960
ꢀ1.863915 ꢀ5.933442 ꢀ1.859045
ꢀ1.607560 ꢀ6.915024 0.418294
ꢀ2.672846 ꢀ5.490117 0.268534
Int-3
PBE/TZVP Energy : ꢀ1544056.66 kcal/mol
C
C
C
C
C
1.284287 ꢀ1.288436 3.611502
0.161565 ꢀ0.569299 3.186582
ꢀ0.195734 ꢀ0.554846 1.836325
0.573139 ꢀ1.267578 0.910357
1.702540 ꢀ1.984433 1.326565
1
7

Dalton Transactions
Page 24 of 57
View Article Online
DOI: 10.1039/C6DT04893E
C
N
2.052342 ꢀ1.993094 2.677569
0.227488 ꢀ1.260872 ꢀ0.477078
Si 0.616427 0.372607 ꢀ1.802039
Cl 0.905176 1.972862 ꢀ3.393408
Cl 2.662565 ꢀ0.519128 ꢀ2.118010
N
C
C
C
C
C
C
C
N
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
ꢀ0.955854 1.248814 ꢀ1.124370
ꢀ0.231583 2.028019 ꢀ0.311986
ꢀ0.748917 3.229158 0.400621
ꢀ1.303318 3.153680 1.684226
ꢀ1.774835 4.309574 2.311884
ꢀ1.696946 5.544811 1.660613
ꢀ1.145703 5.622173 0.376437
ꢀ0.673322 4.469322 ꢀ0.253065
1.043127 1.600354 ꢀ0.356311
2.278854 2.187163 0.252781
2.002012 3.195306 1.382774
ꢀ2.391596 1.310639 ꢀ1.497396
ꢀ2.747288 2.655888 ꢀ2.159635
ꢀ2.648552 0.189560 ꢀ2.518054
ꢀ3.287577 1.063414 ꢀ0.270966
3.090253 2.889405 ꢀ0.851336
3.110794 1.057873 0.886067
ꢀ0.255015 ꢀ2.317910 ꢀ1.049138
ꢀ0.663061 ꢀ3.617233 ꢀ0.519935
ꢀ0.935936 ꢀ3.914517 0.834171
ꢀ1.334907 ꢀ5.197717 1.200533
ꢀ1.460452 ꢀ6.206990 0.236631
ꢀ1.207871 ꢀ5.923119 ꢀ1.109519
ꢀ0.829298 ꢀ4.635728 ꢀ1.485474
ꢀ1.351544 2.195692 2.203597
ꢀ0.239105 4.523279 ꢀ1.253473
ꢀ2.200329 4.243526 3.314801
2.583789 0.632843 1.750067
4.066605 1.474615 1.236541
3.321638 0.256219 0.172059
ꢀ1.081313 6.583394 ꢀ0.136901
ꢀ2.064428 6.446932 2.153658
ꢀ3.053585 0.092646 0.191468
ꢀ4.342609 1.046427 ꢀ0.582217
ꢀ3.170474 1.851941 0.482914
ꢀ2.720186 3.483904 ꢀ1.440713
ꢀ3.764342 2.602244 ꢀ2.575622
ꢀ2.042234 2.873671 ꢀ2.973890
1.542139 4.125352 1.032053
2.972182 3.450132 1.833396
1.370573 2.760565 2.169637
3.367131 2.184426 ꢀ1.644678
4.007952 3.314146 ꢀ0.417315
2.505231 3.701834 ꢀ1.304617
ꢀ2.050519 0.332620 ꢀ3.428040
ꢀ3.711570 0.196940 ꢀ2.796581
ꢀ2.416000 ꢀ0.797799 ꢀ2.095476
0.010024 ꢀ0.530703 ꢀ2.825728
ꢀ0.849224 ꢀ3.144641 1.597794
ꢀ0.645707 ꢀ4.407954 ꢀ2.538217
1
8

Page 25 of 57
Dalton Transactions
View Article Online
DOI: 10.1039/C6DT04893E
H
H
H
H
H
H
H
H
H
ꢀ1.315660 ꢀ6.701834 ꢀ1.866381
ꢀ1.763954 ꢀ7.211917 0.536415
ꢀ1.549702 ꢀ5.414141 2.248581
ꢀ0.368952 ꢀ2.214313 ꢀ2.136417
ꢀ1.080647 ꢀ0.018831 1.494460
2.300413 ꢀ2.519048 0.587104
ꢀ0.444446 ꢀ0.020270 3.910148
2.933884 ꢀ2.550193 3.000126
1.561291 ꢀ1.297573 4.667088
TS-3
PBE/TZVP Energy : ꢀ1544024.87 kcal/mol
C
C
C
C
C
C
C
7.496506 ꢀ3.209226 9.584067
7.531709 ꢀ1.904399 10.065689
6.587501 ꢀ0.958644 9.610648
5.635776 ꢀ1.340303 8.641218
5.599955 ꢀ2.650200 8.167688
6.528671 ꢀ3.586222 8.640800
6.621468 0.427431 10.057985
Si 8.206504 2.296145 10.555340
Cl 9.994854 0.978468 10.465715
N
C
C
N
C
C
C
C
C
C
C
C
C
C
C
C
C
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
6.768771 3.575149 10.868134
5.456972 3.939531 10.271776
5.548116 3.654696 8.761263
8.511178 3.288498 12.154551
9.703848 3.618275 13.007254
10.782500 4.257877 12.114027
7.354502 3.977267 11.994825
6.767648 4.958995 12.946618
5.929241 4.489073 13.966482
5.338584 5.392070 14.855068
5.586134 6.762713 14.729202
6.427221 7.230905 13.712480
7.015686 6.333048 12.821532
10.254890 2.332428 13.643343
9.399369 4.578444 14.169565
4.328931 3.110924 10.915153
5.120539 5.436698 10.417165
5.747411 3.416908 14.066756
7.666620 6.695934 12.023959
4.685895 5.022319 15.648140
9.521725 1.904398 14.340417
11.164889 2.578028 14.209510
10.516471 1.584861 12.886810
6.624241 8.299867 13.612327
5.124534 7.467346 15.423679
4.498973 2.032547 10.799907
3.366582 3.356885 10.442509
4.252278 3.330821 11.989075
4.851397 5.711428 11.442417
4.257749 5.660016 9.772883
5.963378 6.061716 10.090669
9.158231 5.592766 13.835193
10.307305 4.638648 14.786662
1
9

Dalton Transactions
Page 26 of 57
View Article Online
DOI: 10.1039/C6DT04893E
H
H
H
H
H
H
H
H
H
H
H
H
H
H
8.581744 4.213452 14.805387
11.089149 3.575147 11.311336
11.665002 4.503256 12.723971
10.406264 5.181027 11.651034
6.329807 4.273684 8.301410
4.583133 3.885779 8.289441
5.786675 2.606741 8.538442
7.647737 1.503281 9.250784
8.290765 ꢀ1.596214 10.785152
4.921287 ꢀ0.600785 8.270697
4.854935 ꢀ2.943787 7.426221
6.505476 ꢀ4.611561 8.266398
8.227347 ꢀ3.939458 9.935886
5.877868 1.067059 9.568117
Cl 9.153598 3.775524 9.106204
N
C
C
C
C
H
C
H
C
7.196409 0.820926 11.243175
6.933718 0.134504 12.439723
5.618891 ꢀ0.273070 12.747567
7.965203 ꢀ0.163234 13.347651
5.349424 ꢀ0.964336 13.929390
4.808038 ꢀ0.030122 12.057821
7.686843 ꢀ0.838168 14.535157
8.985541 0.105542 13.086643
6.379488 ꢀ1.243916 14.834603
4.325414 ꢀ1.272317 14.151690
8.501583 ꢀ1.067369 15.225771
6.166933 ꢀ1.775514 15.763976
H
H
H
Int-4
PBE/TZVP Energy : ꢀ1544077.59 kcal/mol
C
C
C
C
C
C
C
1.574105 ꢀ5.248630 0.349526
1.069393 ꢀ4.022160 ꢀ0.091094
ꢀ0.114570 ꢀ3.967248 ꢀ0.839192
ꢀ0.786096 ꢀ5.161882 ꢀ1.134772
ꢀ0.281357 ꢀ6.391470 ꢀ0.699143
0.901430 ꢀ6.438318 0.046501
ꢀ0.654324 ꢀ2.648770 ꢀ1.361446
Si 0.249410 ꢀ0.014082 ꢀ1.214157
Cl 2.054677 ꢀ1.021854 ꢀ2.048667
N
C
C
N
C
C
C
C
C
C
C
C
C
C
C
C
ꢀ1.062904 1.235945 ꢀ0.462635
ꢀ2.533291 1.479475 ꢀ0.526165
ꢀ3.193004 0.235360 ꢀ1.146191
1.095112 1.361539 ꢀ0.277376
2.509844 1.737206 0.058786
3.227315 2.159461 ꢀ1.235499
ꢀ0.084634 2.010101 ꢀ0.028092
ꢀ0.236337 3.355769 0.581195
ꢀ0.511601 3.490964 1.948475
ꢀ0.647565 4.763402 2.507089
ꢀ0.517989 5.901241 1.703325
ꢀ0.250076 5.765373 0.336795
ꢀ0.106040 4.495536 ꢀ0.225982
3.195260 0.522231 0.715516
2.614914 2.889802 1.071739
ꢀ3.116181 1.672144 0.886312
2
0

Page 27 of 57
Dalton Transactions
View Article Online
DOI: 10.1039/C6DT04893E
C
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
ꢀ2.845696 2.700933 ꢀ1.409518
ꢀ0.609138 2.602188 2.574182
0.110149 4.385926 ꢀ1.290394
ꢀ0.856050 4.865250 3.573615
2.727081 0.294999 1.685028
4.251892 0.763331 0.900902
3.153599 ꢀ0.371539 0.085388
ꢀ0.149434 6.650147 ꢀ0.294153
ꢀ0.625687 6.894880 2.142349
ꢀ2.816784 0.843980 1.543852
ꢀ4.213733 1.687904 0.821418
ꢀ2.792108 2.617833 1.336725
ꢀ2.470642 3.630183 ꢀ0.962638
ꢀ3.935392 2.796485 ꢀ1.525418
ꢀ2.398160 2.579526 ꢀ2.405712
2.260906 3.847357 0.675083
3.679718 3.002656 1.319881
2.076236 2.670504 2.003199
3.222142 1.352256 ꢀ1.977606
4.272267 2.422862 ꢀ1.014301
2.733501 3.041198 ꢀ1.669887
ꢀ2.818545 0.037877 ꢀ2.158011
ꢀ4.276053 0.409510 ꢀ1.210330
ꢀ3.028278 ꢀ0.650908 ꢀ0.521547
ꢀ0.177972 ꢀ2.433870 ꢀ2.329572
1.590403 ꢀ3.092823 0.145635
ꢀ1.718458 ꢀ5.128548 ꢀ1.705995
ꢀ0.817691 ꢀ7.313332 ꢀ0.934843
1.294265 ꢀ7.396157 0.394049
2.497100 ꢀ5.276438 0.933201
ꢀ1.733007 ꢀ2.749908 ꢀ1.578115
Cl ꢀ0.398512 0.492286 ꢀ3.207464
N
C
C
C
C
H
C
H
C
H
H
H
ꢀ0.406983 ꢀ1.499747 ꢀ0.480434
ꢀ0.948899 ꢀ1.544326 0.818681
ꢀ2.032098 ꢀ2.386451 1.150955
ꢀ0.393037 ꢀ0.756723 1.848219
ꢀ2.558936 ꢀ2.394638 2.444933
ꢀ2.473483 ꢀ3.039249 0.398804
ꢀ0.932837 ꢀ0.758726 3.133333
0.486826 ꢀ0.148876 1.635294
ꢀ2.027331 ꢀ1.574173 3.444698
ꢀ3.401608 ꢀ3.052860 2.668278
ꢀ0.480061 ꢀ0.130500 3.904100
ꢀ2.445063 ꢀ1.583740 4.452862
TS-4
PBE/TZVP Energy : ꢀ1802264.03 kcal/mol
C
C
C
C
C
C
N
ꢀ1.548922 ꢀ1.100109 1.257421
ꢀ1.562816 ꢀ1.653915 ꢀ0.033502
ꢀ2.786218 ꢀ1.749714 ꢀ0.709406
ꢀ3.964356 ꢀ1.285021 ꢀ0.117556
ꢀ3.939210 ꢀ0.713847 1.157911
ꢀ2.722830 ꢀ0.624280 1.844107
ꢀ0.357739 ꢀ2.228710 ꢀ0.607290
2
1

Dalton Transactions
Page 28 of 57
View Article Online
DOI: 10.1039/C6DT04893E
C
C
C
C
C
C
C
0.149008 ꢀ3.352772 0.252865
ꢀ0.916044 ꢀ4.197319 0.921391
ꢀ0.724234 ꢀ4.585809 2.255814
ꢀ1.635692 ꢀ5.427829 2.901735
ꢀ2.766573 ꢀ5.888567 2.220905
ꢀ2.974941 ꢀ5.498870 0.892885
ꢀ2.057246 ꢀ4.664470 0.251439
Si 0.878298 ꢀ0.977848 ꢀ1.275573
Cl 2.031001 0.006501 ꢀ2.961890
N
C
C
C
N
C
C
C
C
C
C
C
C
C
C
C
C
1.139766 0.292487 0.073400
2.107158 0.515198 1.193775
3.443361 0.978908 0.585619
0.208512 1.121150 ꢀ0.454385
ꢀ0.378592 0.505520 ꢀ1.483581
ꢀ1.271604 1.122201 ꢀ2.525146
ꢀ1.559788 0.058315 ꢀ3.591789
ꢀ0.069319 2.506837 0.007088
ꢀ1.154372 2.771087 0.853373
ꢀ1.382688 4.072771 1.305224
ꢀ0.536512 5.113590 0.907822
0.542778 4.850901 0.056469
0.779909 3.550018 ꢀ0.391400
2.313969 ꢀ0.806248 1.956876
1.616172 1.541372 2.231232
ꢀ2.604901 1.581099 ꢀ1.906452
ꢀ0.598042 2.320753 ꢀ3.222863
Cl 2.617339 ꢀ2.314914 ꢀ1.084011
B
O
C
C
O
C
C
C
C
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
ꢀ0.207106 ꢀ2.969165 ꢀ2.828242
0.656285 ꢀ4.041028 ꢀ2.964471
ꢀ0.103097 ꢀ5.159055 ꢀ3.551027
0.768143 ꢀ5.778386 ꢀ4.640182
ꢀ1.505774 ꢀ3.244087 ꢀ3.244901
ꢀ1.406046 ꢀ4.442508 ꢀ4.093875
ꢀ1.256630 ꢀ3.931576 ꢀ5.530570
ꢀ2.688636 ꢀ5.247930 ꢀ3.947199
ꢀ0.360474 ꢀ6.192167 ꢀ2.456064
ꢀ1.808399 1.953747 1.161884
1.622419 3.340348 ꢀ1.052779
ꢀ2.225958 4.274094 1.968418
1.384897 ꢀ1.126589 2.450663
3.066789 ꢀ0.645045 2.741159
2.668364 ꢀ1.609681 1.304202
1.203686 5.660055 ꢀ0.259388
ꢀ0.718267 6.130581 1.260593
ꢀ3.066276 0.776773 ꢀ1.322500
ꢀ3.292971 1.864351 ꢀ2.716527
ꢀ2.470792 2.455809 ꢀ1.259514
ꢀ0.480151 3.175343 ꢀ2.546642
ꢀ1.236344 2.642626 ꢀ4.059343
0.385115 2.038535 ꢀ3.619042
1.611793 2.569397 1.855955
2.303337 1.501028 3.088207
0.608736 1.293807 2.593790
3.821084 0.236314 ꢀ0.130088
4.191800 1.116334 1.380094
2
2

Page 29 of 57
Dalton Transactions
View Article Online
DOI: 10.1039/C6DT04893E
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
3.317682 1.935595 0.059142
ꢀ0.639718 ꢀ0.246005 ꢀ4.107774
ꢀ2.241789 0.485982 ꢀ4.340010
ꢀ2.036127 ꢀ0.831422 ꢀ3.168084
0.821749 ꢀ2.978868 1.039510
0.151277 ꢀ4.219072 2.798735
ꢀ2.241756 ꢀ4.347754 ꢀ0.775513
ꢀ3.859269 ꢀ5.845955 0.353422
ꢀ3.484819 ꢀ6.540025 2.723168
ꢀ1.464717 ꢀ5.716708 3.941201
0.754224 ꢀ4.001635 ꢀ0.395159
0.281758 ꢀ1.854791 ꢀ2.946446
ꢀ0.345576 ꢀ3.327079 ꢀ5.645140
ꢀ1.222059 ꢀ4.759043 ꢀ6.252578
ꢀ2.118995 ꢀ3.294591 ꢀ5.770100
0.209295 ꢀ6.552517 ꢀ5.185721
1.118431 ꢀ5.025379 ꢀ5.356170
1.646495 ꢀ6.252546 ꢀ4.180300
ꢀ3.537822 ꢀ4.656499 ꢀ4.317865
ꢀ2.630813 ꢀ6.171194 ꢀ4.541608
0.603281 ꢀ6.505627 ꢀ2.030959
ꢀ2.883597 ꢀ5.516965 ꢀ2.901617
ꢀ0.860127 ꢀ7.080715 ꢀ2.867285
ꢀ0.975082 ꢀ5.791150 ꢀ1.643104
ꢀ0.610453 ꢀ1.049244 1.808779
ꢀ2.810036 ꢀ2.219536 ꢀ1.691640
ꢀ2.688840 ꢀ0.194819 2.847997
ꢀ4.908914 ꢀ1.375874 ꢀ0.658443
ꢀ4.860114 ꢀ0.352435 1.619967
Pdt-2
PBE/TZVP Energy : ꢀ1802309.46 kcal/mol
C
C
C
C
C
C
C
N
C
C
N
C
C
ꢀ1.058642 3.608424 1.253971
ꢀ0.622634 3.905925 ꢀ0.045045
ꢀ0.771133 5.201035 ꢀ0.558696
ꢀ1.351408 6.196928 0.230360
ꢀ1.796336 5.899479 1.523375
ꢀ1.652366 4.603309 2.031396
ꢀ0.060395 2.810936 ꢀ0.871297
1.143817 2.183576 ꢀ0.668636
2.367329 2.646914 0.062519
2.639139 1.681544 1.227836
ꢀ0.674882 2.179239 ꢀ1.852804
ꢀ2.044469 2.291417 ꢀ2.406199
ꢀ3.106539 2.682179 ꢀ1.364432
Si 0.759932 0.823348 ꢀ1.851358
Cl 2.471691 ꢀ0.558495 ꢀ1.492581
N
B
O
C
C
C
C
ꢀ0.019623 ꢀ1.847002 1.111453
ꢀ0.246105 ꢀ2.724121 ꢀ0.013074
ꢀ1.385988 ꢀ2.765848 ꢀ0.803894
ꢀ1.088954 ꢀ3.680378 ꢀ1.920913
ꢀ2.368755 ꢀ4.417849 ꢀ2.286478
1.268941 ꢀ2.010670 1.795308
1.231296 ꢀ2.843229 3.065816
2
3