Additive-controlled selective hydrosilylation of aryl alkenes catalyzed by bis(silylene) pincer nickel(II) chloride

Abstract

A new bis(silylene) [SiCSi] pincer nickel(II) chloride 1, [(L)Ni(Cl)] (L = 1,3-((PhC(^tBuN)₂Si)(Et)N)₂C₆H₃), was synthesized by the reaction of the corresponding [SiCSi] pincer preligands LH with NiCl₂(DME). The experiments indicate that complex 1 can efficiently catalyze hydrosilylation of alkenes with the participation of different additives. When KO^tBu was used as an additive, the anti-Markovnikov products were obtained for both aryl alkenes and aliphatic alkenes. But in the case of nBuLi as an additive, the Markovnikov products were formed from aryl alkenes. Further study indicated that a complex containing a Ni–H bond may be the real catalyst when using nBuLi as an additive. The molecular structure of complex 1 was confirmed with the single crystal X-ray diffraction technique. To the best of our knowledge, this is the first example of alkene hydrosilylation catalyzed by a silylene nickel complex.

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Introduction

The transition metal catalyzed alkene hydrosilylation reaction is one of the most commonly used and important pathways for preparing organosilicon compounds.¹ However, how to achieve industrial applications of alkene hydrogenation reactions by replacing precious metal catalysts, such as platinum, with base metals has always been a concern for synthetic chemists. In recent years, extensive research has been conducted on the alkene hydrogenation reactions catalyzed by more environmentally friendly base metal (such as Fe, Co, and Ni) complexes.^2,3 A series of encouraging achievements have been made in this field.^4–13 Compared with the industrial hydrosilylation reactions catalyzed by precious metals such as platinum, the alkene hydrosilylation reactions catalyzed by base metal catalysts still have some shortcomings. For example, the stability, selectivity, and catalytic activity of base metal catalysts cannot meet the requirements of industrialization. Typically, ligands play an important role in regulating the stability, selectivity, and catalytic activity of transition metal complex catalysts.

In recent years, N-heterocyclic silylene (NHSi) ligands have gradually attracted people's attention as analogues of N-heterocyclic carbene (NHC) ligands. In many cases, NHSi ligands have been successfully applied to homogeneous catalytic reactions catalyzed by transition metal complexes and have already exhibited excellent catalytic performance.¹⁴

So far, there have only been a few reports on the catalytic hydrosilylation of alkenes by silylene metal complexes. In 2016, the research results of the Kato team showed that the introduction of silylene ligands into the Karstedt catalyst not only significantly improved the stability of the catalyst but also greatly improved the selectivity and catalytic activity compared with traditional Karstedt catalysts and NHC Pt catalysts.¹⁵ Our latest research also showed that the introduction of silylene ligands into organic phosphorus cobalt complexes can effectively regulate the selectivity and enhance the activity of the catalyst for the hydrosilylation of alkenes.^13g,i So far, there have been no reports on the catalytic hydrosilylation of alkenes by silylene nickel complexes.

In this paper, a bis(silylene) [SiCSi] pincer nickel(II) chloride 1 was synthesized and used as a catalyst for alkene hydrosilylation. The experiments indicate that with the participation of different additives, complex 1 can efficiently catalyze hydrosilylation of alkenes. When KO^tBu was used as an additive, the anti-Markovnikov products were obtained for both aryl alkenes and aliphatic alkenes. With nBuLi as an additive, the Markovnikov products were formed from aryl alkenes. Further study indicated that a complex containing a Ni–H bond may be the real catalyst when using nBuLi as an additive.

Results and discussion

Synthesis of bis(silylene) [SiCSi] pincer nickel complex 1

Preligand LH was added to a solution of NiCl₂(DME) in THF at −78 °C. The reaction solution was warmed to room temperature and stirred for 12 h at r.t. (Scheme 1). The yellow solution gradually turned into dark brown-yellow. The volatiles in the solution were removed in a vacuum and the residue was extracted with n-pentane and diethyl ether. Complex 1 was obtained as orange crystals from diethyl ether solution in a yield of 71%.

Scheme 1 Synthesis of complex 1.

In the ¹H NMR spectrum of complex 1, the peaks of ^tBu-, CH₃- and CH₂ groups appear at 1.44, 1.02, and 3.37 ppm, respectively, with an integral ratio of 18 : 3 : 2. In the ²⁹Si NMR spectrum of complex 1, a signal at 13.84 ppm indicates that the two Si atoms have the same chemical environment. Compared with the chemical shift of Si atoms in ligand LH (−14.7 ppm), the coordination of Si atoms in complex 1 leads to a decrease in electron density on the Si atom, and the ²⁹Si NMR signal of complex 1 is significantly shifted towards downfield. The molecular structure of complex 1 was confirmed by single crystal X-ray diffraction analysis (Fig. 1). Complex 1 has a square-planar structure centered on the Ni atom with a sum of total coordination bond angles of 359.89° (Si1–Ni1–C1 = 82.18(6)°, Si2–Ni1–C1 = 82.21(5)°, Si1–Ni1–Cl1 = 99.14(2)° and Si2–Ni1–Cl1 = 96.36(2)°), slightly deviating from 360°. This indicates that the nickel atom and the four coordination atoms (Si, C, Si and Cl) are essentially coplanar. The two Ni–Si_silylene bond lengths (Ni1–Si1 = 2.1846(6) Å and Ni1–Si2 = 2.1801(6) Å) are slightly longer than those of the related [SiCSi] pincer nickel bromide (2.1737(7) Å and 2.1716(7) Å).¹⁶ It is believed that this is because the Ni(II) center of complex 1 as a chloride has a lower electron cloud density than the Ni(II) center in the bromide. Thus, the π-backbond from the Ni(II) atom to the Si(II) atom in complex 1 is weakened, resulting in a longer Ni–Si bond length in complex 1.

Fig. 1 Molecular structure of complex 1. ORTEP plot of complex 1 at the 50% probability level (the hydrogen atoms are omitted for clarity). Selected bond lengths (Å) and angles (°): Ni1–Cl1 2.2231(5), Ni1–C1 1.9514(2), Ni1–Si1 2.1846(6), Ni1–Si2 2.1801(6); Si1–Ni1–Si2 161.25(2), Cl1–Ni1–C1 178.29(5), Si1–Ni1–C1 82.18(6), Si2–Ni1–C1 82.21(5), Si1–Ni1–Cl1 99.14(2), Si2–Ni1–Cl1 96.36(2).

Catalytic activity of complex 1 for alkene hydrosilylation

Based on the Chalk–Harrod mechanism and the modified Chalk–Harrod mechanism of alkene hydrosilylation, metal hydrides are considered as active intermediates in the catalytic system.¹⁷ Due to the instability of metal hydrides in most cases, metal chlorides are commonly used as catalyst precursors for alkene hydrosilylation reactions. The use of additives in this process plays an important role in promoting the generation of metal hydride species and regulating the activity and selectivity of the catalyst. In 2017, Thomas' group used a [NNN] pincer iron(II) chloride complex as a catalyst to achieve the anti-Markovnikov addition reaction of alkenes under the action of NaO^tBu. In this catalytic system, NaO^tBu acts as an activator to promote the generation of active iron intermediates.¹⁸ In 2018, Lu's group discovered that in the iron-catalyzed hydrosilylation of unactivated terminal alkenes, NaO^tBu and PhSiH₃ reduce the [NNN] pincer iron chlorine complex to form an active silyl iron intermediate, which then coordinates with substrate alkene to participate in the catalytic cycle.¹⁹ In 2021, Peng's group systematically studied the effects of various additives such as NaBHEt₃, NaBH₄, NaOEt, KO^tBu, etc. on the alkene hydrosilylation reaction and found that KO^tBu was the most effective. KO^tBu could greatly reduce the activation energy and improve the reaction rate.²⁰ In 2024, Streuff's group discovered that Cp₂ZrCl₂ could effectively catalyze the hydrosilylation of alkenes with the participation of LiOMe. It is believed that the addition of LiOMe promotes the formation of the active catalyst zirconium hydride.²¹ Recently, we reported the synthesis of a novel dinuclear silylene cobalt complex. It was found that the catalytic activity of this complex on the hydrosilylation of alkenes could be promoted with NaBHEt₃ as an additive and a complete conversion with excellent selectivity of 98 : 2 (b : l) could be reached at 120 °C within 8 min for aryl alkenes.^13f

Inspired by the above research results, we used the reaction of styrene with Ph₂SiH₂ as a template reaction to explore the catalytic effect of complex 1 on alkene hydrosilylation with the participation of different additives. The results are summarized in Table 1. From entries 1–4 in Table 1, it can be seen that when the loading of catalyst was 1 mol% and the reaction was carried out at 70 °C for 30 min under solvent-free conditions, the catalyst has the best catalytic activity and selectivity with KO^tBu as an additive. The substrate conversion rate is 100% and the selectivity is 23 : 77 (entry 3, Table 1). When NaHBEt₃ was used as an additive, although complete substrate conversion could also be achieved under the same conditions, the selectivity is 49 : 51 (entry 4, Table 1). The reaction temperature has a significant effect on the reaction selectivity, and 70 °C is the optimal temperature for the reaction (entries 3, 5 and 6, Table 1). Considering both the conversion rate and selectivity, the catalytic system performs best under solvent-free conditions (entries 3 and 7–11, Table 1). Further experiments have shown that the best catalytic effect could be achieved when using Ph₂SiH₂ as silane (entries 3 and 12–16, Table 1). When the catalyst loading was increased to 2 mol%, the selectivity of the catalytic system decreased from 23 : 77 to 39 : 61. Although the selectivity slightly increased when the catalyst loading was reduced to 0.5 mol%, the conversion rate decreased from 100% to 73% (entries 3, 17 and 18, Table 1). Finally, under the reaction conditions of entry 3, we further optimized the reaction conditions by changing the order of substrate addition. The results show that the order of substrate addition has a significant impact on the reaction selectivity (entries 19 and 20, Table 1). When catalyst 1 was pre-reacted with styrene for 30 min, Ph₂SiH₂ was added and the reaction was continued for another 30 min, the conversion rate was 100%, and the selectivity could reach 3 : 97 (entry 19, Table 1). When catalyst 1 was pre-reacted with Ph₂SiH₂ for 30 min, styrene was added and the reaction was continued for another 30 min, the selectivity reached only 14 : 86 although the conversion rate was also 100% (entry 20, Table 1). Therefore, we consider that the reaction conditions of entry 19 in Table 1 were the optimal catalytic conditions.

Table 1 Optimization of reaction conditions^a

Entry	Loading (mol%)	Additive	Solvent	Temp. (°C)	Silane	Conv. (%)	Ratio^b (b/l)
a Catalytic reaction conditions: alkene (1.0 mmol), Ph2SiH2 (1.2 mmol). Conversions and product ratios were determined using GC with n-dodecane as an internal standard. b b/l: branched to linear ratio. c Pre-reacted with styrene for 30 min. d Pre-reacted with Ph2SiH2 for 30 min.
1	1	—	Neat	70	Ph2SiH2	42	49 : 51
2	1	NaOMe	Neat	70	Ph2SiH2	43	45 : 55
3	1	KO^tBu	Neat	70	Ph2SiH2	100	23 : 77
4	1	NaHBEt3	Neat	70	Ph2SiH2	100	49 : 51
5	1	KO^tBu	Neat	80	Ph2SiH2	100	34 : 66
6	1	KO^tBu	Neat	60	Ph2SiH2	76	64 : 36
7	1	KO^tBu	Toluene	70	Ph2SiH2	100	48 : 52
8	1	KO^tBu	Dioxane	70	Ph2SiH2	77	31 : 69
9	1	KO^tBu	THF	70	Ph2SiH2	82	38 : 62
10	1	KO^tBu	n-pentane	70	Ph2SiH2	100	27 : 73
11	1	KO^tBu	DMSO	70	Ph2SiH2	58	29 : 71
12	1	KO^tBu	Neat	70	PhSiH3	31
13	1	KO^tBu	Neat	70	Ph3SiH	17
14	1	KO^tBu	Neat	70	PhSiHCl2	24
15	1	KO^tBu	Neat	70	Et3SiH	30
16	1	KO^tBu	Neat	70	(EtO)3SiH	25
17	2	KO^tBu	Neat	70	Ph2SiH2	100	39 : 61
18	0.5	KO^tBu	Neat	70	Ph2SiH2	73	21 : 79
19^c	1	KO^tBu	Neat	70	Ph2SiH2	100	3 : 97
20^d	1	KO^tBu	Neat	70	Ph2SiH2	100	14 : 86

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Under the above optimized conditions, we investigated the universality of the catalytic system for substrates of alkene hydrosilylation (Table 2). The results show that the catalytic system provides high yields of anti-Markovnikov addition products for both aliphatic alkenes (1a–1f, Table 2) and aromatic alkenes (1g–1r, Table 2). For aromatic alkenes, both the substrates with electron-withdrawing groups, such as halogens and trifluoromethyl groups, on the benzene ring (1h–1l, Table 2) and the substrates with electron-donating groups, such as methyl, methoxy, and tert-butyl groups on the benzene ring (1m–1p, Table 2), exhibit good tolerance. In addition, the position of the substituent on the benzene ring has little effect on the catalytic reaction.

Table 2 Scope of alkenes for complex 1-catalyzed hydrosilylation^a

a Catalytic reaction conditions: 1 (1 mol%), KO^tBu (1 mol%), pre-reacted with alkene (1.0 mmol) at 70 °C for 30 min, Ph₂SiH₂ (1.2 mmol), solvent-free, 70 °C, 30 min, isolated yields. b GC conversion.

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In order to understand the reaction mechanism of the above catalytic system and the role of KO^tBu as an additive in the catalytic system, we designed and implemented the following three stoichiometric reactions (Scheme 2). Unfortunately, no identifiable species were separated through the three reactions, and the expected hydrido nickel species were not detected using in situ IR and ¹H NMR spectroscopy to track the reaction of (b) in Scheme 2 at low temperatures. Combining these results and the literature report,¹⁸ we speculate that the addition of KO^tBu promotes the generation of unknown active species, thereby enhancing the activity and selectivity of the catalyst. Obviously, the catalytic mechanism by complex 1 is different from that with the [NNN] pincer nickel chloride reported by Hu.⁹ Unlike this, when nBuLi is used as an additive, it is found that the hydrido nickel complexes are possible active intermediates (as shown in the experiment below).

Scheme 2 The stoichiometric reactions of complex 1 with KO^tBu.

Regulation of selectivity by nBuLi

The above results indicate that it is possible to change the selectivity of the catalytic system if an appropriate additive is chosen to achieve the generation of intermediate containing the Ni–H bond(s). Thus, we further investigated the influence of nBuLi as an additive on the reactivity and selectivity of the catalytic system (Table 3). It can be seen from entries 1 and 2 in Table 3 that the conversion rate under solvent-free conditions at 70 °C for 30 min is 85%, and the selectivity is 98 : 2 when using styrene and Ph₂SiH₂ as template substrates, nBuLi as an additive, and 1 mol% complex 1 as a catalyst. Compared with the catalytic system using the KO^tBu additive, the selectivity for the reaction of aromatic alkenes shifted from the anti-Markovnikov addition product to the Markovnikov addition product. When the reaction time was extended to 60 min, complete conversion could be achieved with a reaction selectivity of 99 : 1. When the catalyst loading was reduced to 0.5 mol% with 30 min reaction time, the conversion rate was 70% although the selectivity was 99 : 1 (entry 3, Table 3). However, quantitative conversion could also be achieved after 60 min while the reaction selectivity (99 : 1) remained unchanged (entry 4, Table 3).

Table 3 Regulation of selectivity by nBuLi^a

Entry	Loading (mol%)	Time (min)	Conv. (%)	Ratio^b (b/l)
a Catalytic reaction conditions: styrene (1.0 mmol), Ph2SiH2 (1.2 mmol). Conversions and product ratios were determined using GC with n-dodecane as an internal standard. b b/l: branched to linear ratio.
1	1	30	85	98 : 2
2	1	60	100	99 : 1
3	0.5	30	70	99 : 1
4	0.5	60	100	99 : 1

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Under the conditions of entry 4 in Table 3, we further expanded the range of substrates (Table 4). It is found that aliphatic alkenes provided anti-Markovnikov products (1a–1f, Table 4) while aromatic alkenes gave rise to Markovnikov products (2g–2p, Table 4). The experimental results show that the catalytic system has good tolerance to different substrates bearing various substituents with good yields and excellent regioselectivity.

Table 4 Scope of alkenes for complex 1-catalyzed hydrosilylation with nBuLi as an additive^a

a Catalytic reaction conditions: 1 (0.5 mol%), n-BuLi (0.5 mol%), alkene (1.0 mmol), Ph₂SiH₂ (1.2 mmol), solvent-free, 70 °C, 60 min, isolated yields.

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To understand the reaction mechanism of the catalytic system with nBuLi as an additive, we further investigated the stoichiometric reaction between complex 1 and nBuLi (Scheme 3). An absorption signal at 1703 cm⁻¹ corresponding to the Ni–H bond was observed in the in situ IR spectrum of the reaction solution after reacting for 15 min at −80 °C (Fig. S61).²² Meanwhile, in the ¹H NMR of the reaction mixture, the signals were observed at −10.0 and −16.96 ppm, indicating that a hydrido nickel intermediate A was formed during the reaction (Scheme 3, Fig. S62).²² It is believed that the peak at −16.96 ppm is the hydrido signal of intermediate A, while the peak at −10.0 ppm belongs to the hydrogen signal of the semi-activated Csp2–H bond. It is speculated that hydrido intermediate A is unstable in solution and can transform into Ni(0) species with semi-activated η²-(Csp2–H) coordination via reductive elimination. In general, compared to the signals of metal hydrides, the hydrogen signal of η²-(Csp2–H) appears at lower field (downfield). It is believed that intermediate A was generated by β-H elimination of a butyl nickel complex. When the reaction time was further prolonged to 2 h, the signal at 1703 cm⁻¹ disappeared in the in situ IR spectrum, indicating that the species containing the Ni–H bond was unstable (Fig. S63). Under the same conditions, no Ni–H bond vibration or hydrido resonance was observed in the in situ IR spectrum or ¹H NMR of the three-component reaction of complex 1, nBuLi, and styrene. This suggested that intermediate A could rapidly convert to the benzyl nickel intermediate Cvia the C=C insertion reaction of styrene to the Ni–H bond (Scheme 3). In addition, it was found that the conversion rate of the reaction gradually decreased as the pre-reaction time between complex 1 and n-BuLi increased (Table 5). This means that the hydrido intermediate A is unstable.

Scheme 3 The stoichiometric reactions of complex 1 with nBuLi.

Table 5 Effect of pre-reaction time on complex 1 and nBuLi^a

Entry	Pre-reaction time for 1 and nBuLi (min)	Conv. (%)	Ratio^b (b/l)
a Catalytic reaction conditions: 1 (0.5 mol%), nBuLi (0.5 mol%), styrene (1.0 mmol), Ph2SiH2 (1.2 mmol), solvent-free, 70 °C, 60 min. b b/l: branched to linear ratio.
1	0	100	99 : 1
2	30	84	98 : 2
3	60	80	93 : 7

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Based on the above experimental results and relevant reference,^13i,23 a possible mechanism for the catalytic system of complex 1 involving nBuLi as an additive is proposed, as shown in Scheme 4. Firstly, complex 1 reacts with nBuLi via β-H elimination to form nickel hydride intermediate A, which then coordinates with an alkene substrate to give rise to intermediate B. For an aromatic substrate, the coordinated alkene is inserted into the Ni–H bond via 2,1-insertion to form intermediate C. For an aliphatic substrate, the coordinated alkene is inserted into the Ni–H bond via 1,2-insertion to form intermediate E. Then, C or E interacts with Ph₂SiH₂ to produce a four-membered transition state D or F. Finally, through the σ-bond metathesis reaction, a Markovnikov product or an anti-Markovnikov product is generated, respectively. At the same time, active intermediate A is re-generated to finish the catalytic cycle. When styrene was used as the substrate, the presence of intermediates B/C and D in the catalytic reaction solution was detected using HRMS(ESI) after the start (30 min) of the reaction. Unfortunately, we were unable to find the molecular ion peaks of intermediates B/E and F using HRMS(ESI) when 1-heptene was used as the substrate (see the SI for details).

Scheme 4 Proposed catalytic mechanism.

Conclusion

In summary, a novel bis(silylene) [SiCSi] pincer nickel(II) chloride complex 1 was synthesized through the reaction of preligand LH with NiCl₂(DME). The experiments indicate that complex 1 can efficiently catalyze hydrosilylation of alkenes with the participation of different additives. When KO^tBu was used as an additive, the anti-Markovnikov products were obtained for both aryl alkenes and aliphatic alkenes. When KO^tBu was replaced by nBuLi, the Markovnikov products were formed from aryl alkenes. Further study indicates that an active hydrido nickel species containing the Ni–H bond is believed as a real catalyst when using nBuLi as an additive. To our knowledge, this is the first example of alkene hydrosilylation catalyzed by a silylene nickel complex.

Experimental section

General procedures and materials

All reactions and operations were carried out under nitrogen protection using standard Schlenk technology. The solvents used in the experiment were dehydrated and degassed, and all other chemicals were purchased and used without further purification. Ligand LH was prepared according to the reported procedure.^13d Gas chromatography was performed by using a Shimadzu GC 2014 instrument with n-dodecane as an internal standard. Infrared spectra (4000–400 cm⁻¹) were recorded on a Bruker ALPHA FT-IR instrument by using Nujol mulls between KBr disks. ¹H, ¹³C, ³¹P, and ²⁹Si NMR spectra were obtained by using Bruker Avance 300 and 500 MHz spectrometers.

Caution! (EtO)₃SiH is flammable and highly toxic by inhalation and may cause skin irritation and blindness. Even if during our studies on the hydrosilylation of alkenes, we used it without incident, triethoxysilane should be used with precaution. Indeed, due to possible silane disproportionation, the formation of an extremely pyrophoric gas (possibly SiH₄) has led to several fires and explosions reported in the literature (see Buchwald safety letter, Chemical & Engineering News (29 Mar 1993) Vol. 71, No. 13, pp. 2.). In addition, PhSiH₃ and Me(EtO)₂SiH are also highly flammable.

Synthesis of complex 1

LH (1.00 g, 1.47 mmol) in 35 mL of THF was slowly added into the solution of NiCl₂(DME) (0.36 g, 1.62 mmol) in 35 mL of THF at −78 °C under a N₂ atmosphere. The reaction solution was warmed to room temperature and stirred overnight, and the yellow solution gradually turned deep brown-yellow. The volatiles in the reaction mixture were removed under vacuum. The residue was extracted with n-pentane and diethyl ether. Complex 1 as orange crystals precipitated from the solution in the yield of 71% (0.81 g). ¹H NMR (400 MHz, C₆D₆, 298 K, ppm): δ 7.26 (s, 10H, Ar–H), 7.09–6.99 (m, 3H, Ar–H), 3.44 (dd, J = 60.0, 7.0 Hz, 4H, CH₂), 1.45 (d, J = 8.8 Hz, 36H, ^tBu), 1.02 (t, J = 6.8 Hz, 6H, CH₃). ¹³C NMR (101 MHz, C₆D₆, 298 K, ppm): δ 170.54, 158.47, 131.28, 130.11, 128.71, 127.54, 127.27, 126.40, 126.02, 100.76, 52.66, 30.10, 29.03, 14.51. ²⁹Si NMR (79 MHz, C₆D₆, 298 K, ppm): δ 13.84 (s).

General procedure for nickel-catalyzed hydrosilylation

Under a N₂ atmosphere, complex 1 (1 mol%) was added to a 20 mL Schlenk tube containing a magnetic stirrer. Styrene (0.11 g,1.0 mmol), diphenylsilane (0.22 g, 1.2 mmol), and n-dodecane (0.17 g, 1.0 mmol) were added in order. The mixture was stirred at 70 °C for 0.5 h. The reaction solution was quenched with ethyl acetate. The combined organic fractions were concentrated in a vacuum and the crude product was purified by column chromatography on silica gel with petrol ether as the eluent. The pure product was characterized by NMR analysis.

X-ray crystal structure determination

Single crystal X-ray diffraction data for complex 1 were collected on a Rigaku Oxford Diffraction XtaLAB Synergy-S diffractometer equipped with Cu Kα radiation (λ = 1.54184 Å). During collection of the intensity data, no significant decay was observed. The structure was resolved by the OLEX2 program²⁴ and refined on F² with SHELXL.²⁵ All non-hydrogen atoms were refined anisotropically, and all hydrogen atoms were placed using AFIX instructions. The t-Bu group is modelled as disordered.

Conflicts of interest

There are no conflicts to declare.

Data availability

The data that support the findings of this study are available in the supplementary information (SI) of this article. Supplementary information: crystallographic data, IR, ¹H, ³¹P, ¹³C and ²⁹Si NMR spectra of complex 1, ¹H and ¹³C spectra of catalytic products, and IR, ¹H NMR and HRMS spectra for mechanistic study. See DOI: https://doi.org/10.1039/d5nj03998c.

CCDC 2402419 (1) contains the supplementary crystallographic data for this paper.²⁶

Acknowledgements

This work was supported by the Natural Science Foundation of Shandong Province ZR2019ZD46/ZR2021MB010.

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