Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Includes bibliographical references. / by Jere Douglas Fellmann. / Ph.D.

This project was focused on the synthesis and reactivity of rare-earth nbutyl complexes of the formula [CpMe2M(μ-nBu)]2 (where M = Y, Dy). Dysprosium was used as it has a large magnetic moment which is favourable for producing single molecule magnets (SMMs). Yttrium was used as a diamagnetic analogue to examine the reactivity of [CpMe2Y(μ- nBu)]2 in solution, and provide further characterisation of isolated complexes with NMR spectroscopy. Another goal of the project was to establish the reactivity of [CpMe2M(μ- nBu)]2 with respect to the commonly used alkylating reagent nbutyllithium (nBuLi). It was found that the nbutyl complexes are remarkably stable in solution and the solid state, allowing for the synthesis to be scaled up and for the nbutyl complexes to be used as starting materials. The reactivity of [CpMe2M(μ- nBu)]2 towards ferrocene was investigated. The product was a ferrocenyl-bridged dimer of the formula [CpMe2M(μ-(C5H4)FeCp)]2 resulting from a single deprotonation of ferrocene. The reactivity of [CpMe2M(μ- nBu)]2 towards N-heterocyclic carbenes (NHCs) was also investigated. No reaction occurred between [CpMe2Y(μ- nBu)]2 and 1,3-bis-(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr), a reaction did occur between [CpMe2Y(μ- nBu)]2 and 1,3-bis-(tert-butyl)imidazol-2-ylidene (ItBu) but no crystalline product could be obtained. [CpMe2M(μ- nBu)]2 reacts with 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes) to form a monomeric, benzyl tethered carbene complex [CpMe2M(IMes’)]. An ortho-methyl group on one of the mesityl substituents is deprotonated generating an asymmetric functionalised carbene. A control experiment between CpMe3M (M = Dy, Y) and IMes resulted in the formation of the abnormal, rearranged carbene complexes [CpMe3M(aIMes)]. C6H6. Structural analysis revealed a very short C-H---π interaction between neighbouring molecules. The mechanism of carbene rearrangement was probed by 1H NMR spectroscopy (M = Y). Magnetic susceptibility measurements revealed that [CpMe2Dy(μ- nBu)]2, [CpMe2Dy(μ-(C5H4)FeCp)]2, [CpMe2Dy(IMes’)] and [CpMe3Dy(aIMes)]. C6H6 are not SMMs. [CpMe2M(μ- nBu)]2 activates sulfur and selenium to form hexanuclear clusters of the formula [CpMe10M((E3)2E2] (M = Dy, Y; E = S, Se). [CpMe10M((S3)2S2] is an SMM with an energy barrier to magnetisation reversal, Ueff, of 73 cm-1. The analogous selenium cluster could be characterised by single crystal X-ray diffraction however separation from unreacted selenium proved difficult without using coordinating solvent. Extraction of [CpMe10Y((Se3)2Se2] with THF resulted in the crystallisation of the ion pair [CpMe2Y(THF)3][{CpMeY(Se2)}6Se] and [{CpMe2Y(THF)}(µ-Se2)]. A trimetallic dysprosium coordination complex containing a hexaazatrinapthalene (HAN) bridging ligand is reported. Magnetic measurements on [{(thd)3Dy}3HAN] (Dy3HAN) show that it is an SMM in zero field and two magnetic relaxation mechanisms are present. An optimised DC field of 1 kOe allowed for better resolution of the two relaxation processes and an energy barrier for each process could be extracted. The Ueff barriers are 42 and 52 cm-1. Ab initio theoretical analysis revealed the magnetic anisotropy axes are nearly collinear precluding the presence of a toroidal magnetic moment. The ground state of Dy3HAN was found to be frustrated.

Lau Cheuk Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 93-98). / Abstracts in English and Chinese. / Table of Contents --- p.i / Acknowledgements --- p.iii / Abbreviations --- p.iv / Structural Abbreviations for Porphyrin Complexes --- p.v / Abstract --- p.vi / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- General Introduction --- p.1 / Chapter 1.2 --- Activation of Carbon-Hydrogen Bond (CHA) by Transition Metal --- p.2 / Chapter 1.2.1 --- Application of CHA by Transition Metals --- p.3 / Chapter 1.2.2 --- Thermodynamic in CHA by Transition Metals --- p.5 / Chapter 1.2.3 --- Types of Carbon-Hydrogen Activations --- p.6 / Chapter 1.3 --- Carbon-Hydrogen Bond Activation of Aldehydes --- p.14 / Chapter 1.3.1 --- Catalytic Application of CHA of Aldehydes by Transition Metals --- p.14 / Chapter 1.3.2 --- Stability of Intermediate M(COR) --- p.15 / Chapter 1.3.3 --- Issue in Selectivity --- p.16 / Chapter 1.4 --- Structural Features of Rhodium Porphyrins --- p.23 / Chapter 1.5 --- Objective of the work --- p.24 / Chapter Chapter 2 --- Carbon-Hydrogen Activation of Aldehydes by Rh(ttp)Cl and Rh(ttp)Me / Chapter 2.1 --- Introduction --- p.26 / Chapter 2.2 --- CHA of Aldehydes by Rh(ttp)Cl --- p.27 / Chapter 2.2.1 --- Preparation of Rh(ttp)Cl --- p.27 / Chapter 2.2.2 --- Solvents Screening --- p.27 / Chapter 2.2.3 --- Results and Discussion --- p.30 / Chapter 2.3 --- CHA of Aldehydes by Rh(ttp)Me --- p.33 / Chapter 2.3.1 --- Preparation of Rh(ttp)Me --- p.34 / Chapter 2.3.2 --- Results and Discussion --- p.35 / Chapter 2.4 --- Mechanistic Studies --- p.37 / Chapter 2.4.1 --- CHA of Aldehydes by Rh(ttp)Cl --- p.37 / Chapter 2.4.2 --- CHA of Aldehydes by Rh(ttp)R --- p.42 / Chapter 2.5 --- Comparison of the u(C=0) --- p.48 / Chapter 2.6 --- X-ray Data --- p.49 / Chapter 2.7 --- Summary --- p.50 / Chapter Chapter 3 --- CHA of Aldehydes by Rh(ttp)CH2CH2OH and Rh(ttp)+X- / Chapter 3.1 --- Introduction --- p.52 / Chapter 3.2 --- CHA of Aldehydes by Rh(ttp)CH2CH2OH --- p.53 / Chapter 3.2.1 --- Results and Discussion --- p.53 / Chapter 3.2.2 --- Mechanistic Studies --- p.61 / Chapter 3.3 --- CHA of Aldehydes by Rh(ttp)+X- --- p.65 / Chapter 3.4 --- Summary --- p.67 / Conclusion --- p.68 / Experimental --- p.69 / Reference --- p.93 / Appendix I Crystal Data and Processing Parameters --- p.99 / List of Spectra --- p.141 / Spectra --- p.143

Chong Kim Hung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references. / Abstracts in English and Chinese. / Table of contents --- p.vi / Acknowledgements --- p.i / Abstract --- p.ii / 摘要 --- p.iv / List of Compounds --- p.ix / Synthesized / Abbreviations --- p.x / Chapter Chapter 1 --- Reactivity of Pyridyl-1-azaallyl Enamido Germanium(II) Chloride / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.1.1 --- General Aspects of Reactivity of Heteroleptic Germylenes --- p.1 / Chapter 1.1.2 --- Synthesis of Pyridyl-1 -azaallyl Germanium(II) Chloride Complex --- p.10 / Chapter 1.1.3 --- Objectives of This Work --- p.12 / Chapter 1.2 --- Results and Discussion --- p.14 / Chapter 1.2.1.1 --- Synthesis of Chalcogenonyl Halide Complexes --- p.15 / Chapter 1.2.1.2 --- Spectroscopic Properties of 33 and 34 --- p.15 / Chapter 1.2.1.3 --- "Molecular Structures of [Ge(E){N(SiMe3)C(Ph)- C(SiMe3)(C5H4N-2)}Cl] (E = S (33), Se (34))" --- p.16 / Chapter 1.2.2.1 --- Synthesis of Group 11 Transition Metal-Pyridyl-1- Enamido Germanium(II) Chloride Complexes --- p.20 / Chapter 1.2.2.2 --- Spectroscopic Properties of 35 and 36 --- p.21 / Chapter 1.2.2.3 --- Molecular Structures of [Ge(CuI){N(SiMe3)- C(Ph)C(SiMe3)(C5H4N-2)}Cl(THF)2]4 (35) and [Ge(AuI){N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}Cl] (36) --- p.22 / Chapter 1.2.3.1 --- "Reaction of Pyridyl-l-azaallyl Germanium(II) Chloride with 3,5-di-tert butyl-o-benzoqumone: Synthesis of [Ge{O(2,4-di-Bu'-C6H2)O}{N(SiMe3)C(Ph)C(SiMe3)- (C5H4N-2)}C1] (37)" --- p.27 / Chapter 1.2.3.2 --- Spectroscopic Properties of 37 --- p.27 / Chapter 1.2.3.3 --- "Molecular Structure of [Ge{0(2,4-di-Bu'- C6H2)O} {N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}Cl] (37)" --- p.28 / Chapter 1.2.4.1 --- Synthesis of Boron-Germanium(II) Hydride Adduct --- p.31 / Chapter 1.2.4.2 --- Spectroscopic Properties of 38 --- p.31 / Chapter 1.2.4.3 --- Molecular Structure of [Ge(BH3){N(SiMe3)C(Ph)- C(SiMe3)(C5H4N-2)}H] (38) --- p.32 / Chapter 1.2.5.1 --- Substitution Reaction of Pyridyl-l-azaallyl Germanium(II) Chloride with Lithium Phenylacetylide --- p.34 / Chapter 1.2.5.2 --- Spectroscopic Properties of 39 --- p.34 / Chapter 1.2.5.3 --- Molecular Structure of [Ge{N(SiMe3)C(Ph)C(SiMe3)- (C5H4N-2)}(CCPh)] (39) --- p.35 / Chapter 1.2.6.1 --- Reaction of Pyridyl-l-azaallyl Germanium(II) Chloride with excess lithium; the formation of [GeC(Ph)C(SiMe3)(C5H4N-2)]2 (40) --- p.38 / Chapter 1.2.6.2 --- Spectroscopic Properties of 40 --- p.38 / Chapter 1.2.6.3 --- Molecular Structure of [GeC(Ph)C(SiMe3)(C5H4N-2)]2 (40) --- p.39 / Chapter 1.3 --- Experimental for Chapter 1 --- p.43 / Chapter 1.4 --- References for Chapter 1 --- p.50 / Chapter Chapter 2 --- Synthesis of Late Transition Metal Pyridyl-l-azaallyl Complexes / Chapter 2.1 --- Introduction --- p.55 / Chapter 2.1.1 --- General Aspects of 1 -azaallyl Metal Complexes --- p.55 / Chapter 2.1.2 --- Synthesis of Pyridyl-l-azaallyl Metal Complexes --- p.61 / Chapter 2.2 --- Results and Discussion --- p.68 / Chapter 2.2.1 --- Synthesis of Late Transition Metal Pyridyl-l-azaallyl Complexes --- p.68 / Chapter 2.2.2 --- Spectroscopic Properties of 55-59 --- p.70 / Chapter 2.2.3 --- Molecular Structures of Compounds 55-59 --- p.71 / Chapter 2.3 --- Experimental for Chapter 2 --- p.80 / Chapter 2.4 --- References for Chapter 2 --- p.83 / Appendix I / Chapter A. --- General Procedures --- p.86 / Chapter B. --- Physical and Analytical Measurements --- p.86 / Appendix II / Table A.1. Selected Crystallographic Data for Compounds 33-36 --- p.89 / Table A.2. Selected Crystallographic Data for Compounds 37-40 --- p.90 / Table A.3. Selected Crystallographic Data for Compounds 56-58 --- p.91 / Table A.4. Selected Crystallographic Data for Compound 59 --- p.92

Chapter 1 describes the reactivities of bisgermavinylidene [(Me 3SiN=RPh2)2C=Ge→Ge=C(PPh2=NSiMe 3)2] (25). With the use of CpMnCO2(THF), Mn2(CO)10 and group 11 metal halides, manganese-germavinylidene complexes and germavinylidyl group 11 metal complexes were prepared respectively. Radical reaction of 25 with 2,2,6,6-tetramethylpiperidine N-oxide affords [(Me3SiN=RPh2)2C=Ge(ONCMe2C 3H6CMe2)2] (40). Cycloadditon reactions of 25 were studied. The reaction of 25 with benzil, azobenzene or 3,5-di-tert-butyl-o-benzoquinone affords [(Me3SiN=PPh2)2C=Ge{O(Ph)C=C(Ph)O}] (41), [(Me3SiN=PPh2)2C=Ge( o-C6H4NHNPh)](42) and [(Me 3SiN=PPh2)2C=Ge=C-(PPh2=NSiMe 3)2] (44), respectively. The C=Ge bond of 25 can undergo cycloaddition reactions with Me3SiN 3, Me3SiCHN2 or AdNCO (Ad = adamantly) to give [(Me3SiN=PPh2)2CGeN(SiMe3)N=N] (46), [(Me3SiN=PPh2)2C-GeN=NCH-SiMe 3] (48) and [(Me3SiN=PPh2)2 CGeN(Ad)C-O] (47), respectively. Furthermore, 1,2-addition products of rhodium(I) and tin(IV) complexes were prepared from the reaction of 25 with (cod)RhCl and (nBu) 3SnN3, respectively. The syntheses of bimetallic chlorides [(Me3SiN=PPh2)2(GcCl)CMn(mu-Cl)]2 (51) and [(Me3SiN=PPh2)2(GeCl)CFeCl] (52) are also reported. / Chapter 2 concerns the reactivities of bis(iminophosphorano)methanide tin(II) chloride [HC(PPh2=NSiMe3)2SnCl] ( 79). The reactivity of the lone pair in 79 was studied. The reaction of 79 with benzil or 3,5-di-tert-butyl- o-benzoquinone gives the corresponding cycloaddition products. Treatment of 79 with NaN3 or AgOSO2CF3 affords the corresponding substituted heteroleptic stannylenes. The reaction of 79 with W(CO)5THF gives an adduct [HC(PPh 2=NSiMe3)2(Cl)Sn→W(CO)5] ( 81). Compound 79 reacts with Fe{N(SiMe3) 2}2 to afford [HC(PPh2=NSiMe3) 2Fe(mu-Cl)]2 (86). Moreover, treatment of 79 with LiC≡CPh gives [HC(PPh2=NSiMe3) 2C(Sn)=C(Ph)Sn(C≡CPh)2]2 (87). / Chapter 3 deals with the preparation and characterization of group 14 bis(thiophosphinoyl) metal complexes. The newly developed ligand [(S=PPr i2CH2)2-C5H 3N-2,6] (126) undergoes metalation with nBuLi or (nBu)2Mg to afford the lithium complex [Li{(S=PPri 2CH)(S=PPi2CH2)C 5H3N-2,6}(Et2O)] (127) and magnesium complex [Mg(S=PPri2CH)2C 5H3N-2,6] (128), respectively. 1,3-Distannylcyclobutane and 1,3-diplumbacyclobutane were prepared from treatment of 126 with M{N(SiMe3)2}2 (M Sn, Pb) by the amine-elimination reaction. Furthermore, compound 127 reacts with GeCl2.dioxane or SnCl2 to afford digermylgermylene Ge[GeCl2{(S=PPr i2CH)(S=PPri 2CH2)C5H3N-2,6}]2 ( 131) and ionic tin(II) complex [{C5H3N-2,6-(CH 2PPri2=S)(CHPPr i2=S)}SN+][SnCl3 -] (134), respectively. / Chapter 4 describes the conclusion of the first three chapters. The future works of the first three chapters were also reported. / This thesis is focused on four areas: (i) the reactivities of bisgermavinylidene; (ii) the reactivities of bis(iminophosphorano)methanide tin(II) chloride; (iii) the synthesis of group 14 bis(thiophosphinoyl) metal complexes and (iv) conclusions and future works. / Kan, Kwok Wai. / "Aug 2007." / Adviser: Kevin W. P. Leung. / Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 1007. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.

This thesis presents a detailed theoretical/computational analysis using quantum chemistry to investigate the thermochemistry and reaction mechanisms of palladacycles that underpin experimental observations. The thesis begins by establishing a suitable computational methodology for the study of pincer palladacycles. It was found that Density Functional Theory (DFT) was suitable for the accurate reproduction of geometric structures and energetics by comparing a range of commonly used density functionals and basis sets with the X-ray crystal structures of symmetric pincer palladacycles. The detailed electronic structure of several pincer palladacycles was investigated using Complete Active Space Self-Consistent Field method (CASSCF) and it was shown that the dominant configuration was larger than 0.96, indicating that the ground state electronic structure has significant single-reference character. DFT was used to investigate the stability of symmetrical pincer palladacycles, and then by changing the donor ligand, unsymmetrical pincer palladacycles. The pincer palladacycle formation was investigated and it was found that the barrier to C-H activation was dependent on the ligand arm of the pincer that coordinates to PdCl2. Topological analysis was performed using Quantum Theory of Atoms In Molecules (QTAIM) for determining the strength and nature of the Pd and donor atom interactions, showing that the bond strength depends on the type of donor atom and trans influence in the pincer palladacycles. The mechanism for Pd(0) formation from both symmetrical and unsymmetrical pincer palladacycle pre-catalysts for catalysis in Suzuki-Miyaura carbon-carbon cross-coupling reactions was studied, and then with the introduction of base and the effect of solvent. It was shown that the key steps are transmetallation and reductive elimination processes, and differences in the overall Gibbs free energy and transmetallation barrier provide an explanation for observed catalytic activity. This has been in conjunction with experimental chemists. Finally, the functionalisation of benzodiazepines was investigated in three conditions; with Pd(II)/Ru(II)-catalysts, with Pd(II)-catalysts and without catalyst. It was found that the Ru(II) photocatalyst with Pd(II)-catalyst is the best condition for functionalisation on benzodiazepines with the lowest energy barrier.

No description available.

No description available.

The reactions of carboxylic acids with organoaluminium reagents were studied, which led to the formation of novel aluminium compounds. The reactions of orthofunctionalised derivatives of benzoic acid with trivalent aluminium organyls AlR3, led to the formation of different Al-based molecular clusters, depending on the nature of R, the reaction stoichiometry and the character of the benzoic acid derivative. The obtained compounds were characterised in the solid state by X-ray diffraction methods and two main motifs were observed. When the acid and AlR3 reacted in a one-to-two stoichiometry the obtained products, [iBu4Al2(μ-O2CC6H4-2-μ- O)]2, [(Me2Al)2(μ-O2CC6H4-2-μ-NH)]2, [(iBu2Al)2(μ-O2CC6H4-2-μ-NH)]2, [(Me2Al)2(μ- O2CC6H4-2-μ-NMe)]2 and [(iBu2Al)2(μ-O2CC6H4-2-μ-NMe)]2, consisted of a central distorted 12-membered macrocycle, formed by two [Al-O-C-O-Al-X] units (X= O,N) and was found to be dimeric. The reaction between anthranilic acid derivatives and AlR3 could also take place in a one-to-one ratio. For anthranilic acid and Nmethylanthranilic acid the obtained crystals only allowed a qualitative analysis and showed the structure of the products, [MeAl(μ-O2CC6H4-2-μ-NH)]4, [iBuAl(μ-O2CC6H4- 2-μ-NMe)]4 to be tetrameric and each consisting of a distorted 16-membered ring formed by four [O-C-O-Al] units. With the reaction of N-phenylanthranilic acid it was possible to isolate a structural analogous product [iBuAl(μ-O2CC6H4-2-μ-NPh)]4 which could be fully characterised by x-ray crystallography and NMR spectroscopy. Where the quantity and quality of the obtained product was sufficient, the solution behaviour of the compounds was elucidated by multinuclear and multidimensional NMR spectroscopic techniques. The 27Al NMR showed that the aforementioned aggregates are maintained in solution, which for the 12-membered [Al-O-C-O-Al-N] macrocycle of [(iBu2Al)2(μ-O2CC6H4-2-μ-NH)]2 was confirmed by a NOESY spectrum. The second part of this project focused on the preliminary studies towards the application of aluminium compounds in the crosslinking of guar and carboxymethyl hydroxypropyl guar, which are common additives in hydraulic fracturing. Different commercially available aluminium compounds were tested for their general ability to crosslink the aforementioned polysaccharides, yielding promising results for aluminium lactate, aluminium acetylacetonate and aluminium isopropoxide. For the system comprising aluminium lactate in combination with CMHPG, rheological studies were carried out to determine the viscosity, the viscoelasticity, the shear recovery and the stability towards high temperatures. These sought to evaluate the crosslinking properties of the aluminium additive and to optimise the required conditions of the different system components. Finally, it was possible to obtain first proof-of-concept data suggesting that synthetically obtained aluminium compounds such as [Me2Al(μ- O2CPh)]2 and Al[MeC(CH2O)3]2(AlMe2)3 can be employed for the crosslinking of guar and CMHPG.

Investigation of catalytic main-group bond forming reactions is the basis of this dissertation. Coupling of group 14 and 15 elements by several different methods has been achieved. The influence of Si–N heterodehydrocoupling on the promotion of α-silylene elimination was realized. Efficient Si–N heterodehydrocoupling by a simple, earth abundant lanthanide catalyst was demonstrated. Significant advances in hydrophosphination by commercially available catalysts was achieved by photo-activation of a precious metal catalyst. Exploration of (N3N)ZrNMe2 (N3N = N(CH2CH2NSiMe3)33–) as a catalyst for the cross-dehydrocoupling or heterodehydrocoupling of silanes and amines suggested silylene reactivity. Further studies of the catalysis and stoichiometric modeling reactions hint at α-silylene elimination as the pivotal mechanistic step, which expands the 3p elements known to engage in this catalysis and provides a new strategy for the catalytic generation of low-valent fragments. In addition, silane dehydrocoupling by group 1 and 2 metal bis(trimethylsilyl)amide complexes was investigated. Catalytic silane redistribution was observed, which was previously unknown for d0 metal catalysts. La[N(SiMe3)2]3THF2 is an effective pre-catalyst for the heterodehydrocoupling of silanes and amines. Coupling of primary and secondary amines with aryl silanes was achieved with a loading of 0.8 mol % of La[N(SiMe3)2]3THF2. With primary amines, generation of tertiary and sometimes quaternary silamines was facile, often requiring only a few hours to reach completion, including new silamines Ph3Si(nPrNH) and Ph3Si(iPrNH). Secondary amines were also available for heterodehydrocoupling, though they generally required longer reaction times and, in some instances, higher reaction temperatures. By utilizing a diamine, dehydropolymerization was achieved. The resulting polymer was studied by MS and TGA. This work expands upon the utility of f-block complexes in heterodehydrocoupling catalysis. Stoichiometric and catalytic P–E bond forming reactions were explored with ruthenium complexes. Hydrophosphination of primary phosphines and activated alkenes was achieved with 0.1 mol % bis(cyclopentadienylruthenium dicarbonyl) dimer, [CpRu(CO)2]2. Photo-activation of [CpRu(CO)2]2 was achieved with a commercially available UV-A 9W lamp. Preliminary results indicate that secondary phosphines as well as internal alkynes may be viable substrates with this catalyst. Attempts to synthesize ruthenium phosphinidene complexes for stoichiometric P–E formation have been met with synthetic challenges. Ongoing efforts to synthesize a ruthenium phosphinidene are discussed. The work in this dissertation has expanded the utility of metal-catalyzed main-group bond forming reactions. A potential avenue for catalytic generation low-valent silicon fragments has been discovered. Rapid Si–N heterodehydrocoupling by an easily obtained catalyst has been demonstrated. Hydrophosphination with primary phosphines has been achieved with a commercially available photocatalyst catalyst, requiring only low intensity UV light.