Synthesis of Phosphine-Functionalized Silicon Cubane and Its Oxidative Addition, Giving a Bis(silyl)copper Complex

A new strategy for the introduction of a second type of Si atom to silicon cubanes has been developed starting from the tricyclic hexasilane dianion [Ar6Si6]2– (Ar = 2,4,6-Me3C6H2). Treatment of the dianion with Ar′SiCl3, followed by KC8, gave new types of octasilacubanes Ar6Ar′2Si8 [Ar′ = 2,4,6-iPr2C6H2 (3a), 2-Ph2PC6H4 (3b)] in high yields. Remarkably, treatment of cubane 3b bearing with two phosphine groups with 2 equiv of CuCl in CH2Cl2 yielded the bis(silyl)copper complex via the selective oxidative addition of the newly formed Si–Si bond to Cu ion. Single-crystal X-ray analysis indicated the unique square-planar, four-coordinate Cu cation paired with the [CuCl2]− counteranion

Synthesis and Reactivity of a Base-Free N-Heterocyclic Silanimine

Reaction of the N-heterocyclic silylene (HCNDipp)2Si (1, Dipp = 2,6-iPr2C6H3) with the terphenyl azide ArN3 (Ar = 2,6-Mes2C6H3, Mes =2,4,6-Me3C6H2) in THF yielded the base-free silanimine (HCNDipp)2SiNAr (2) with the almost linear SiNC geometry in high yield. Reaction of 2 with sulfur and H2O resulted in the 1,3-addition of S2 to the C2N2Si ring and 1,2-addition of H2O to the SiN bond, respectively

Synthesis and Reactivity of a Base-Free N-Heterocyclic Silanimine

Reaction of the N-heterocyclic silylene (HCNDipp)2Si (1, Dipp = 2,6-iPr2C6H3) with the terphenyl azide ArN3 (Ar = 2,6-Mes2C6H3, Mes =2,4,6-Me3C6H2) in THF yielded the base-free silanimine (HCNDipp)2SiNAr (2) with the almost linear SiNC geometry in high yield. Reaction of 2 with sulfur and H2O resulted in the 1,3-addition of S2 to the C2N2Si ring and 1,2-addition of H2O to the SiN bond, respectively

Synthesis and Reactivity of a Base-Free N-Heterocyclic Silanimine

Reaction of the N-heterocyclic silylene (HCNDipp)2Si (1, Dipp = 2,6-iPr2C6H3) with the terphenyl azide ArN3 (Ar = 2,6-Mes2C6H3, Mes =2,4,6-Me3C6H2) in THF yielded the base-free silanimine (HCNDipp)2SiNAr (2) with the almost linear SiNC geometry in high yield. Reaction of 2 with sulfur and H2O resulted in the 1,3-addition of S2 to the C2N2Si ring and 1,2-addition of H2O to the SiN bond, respectively

Synthesis of Calcium and Ytterbium Complexes Supported by a Tridentate Imino-Amidinate Ligand and Their Application in the Intermolecular Hydrophosphination of Alkenes and Alkynes

Well-defined calcium and ytterbium complexes [{2-NC­(Ph)­NArC₆H₄CHNAr}­M­{N­(SiMe₃)₂}­(THF)] (M = Ca, Yb; Ar = 2,6-<i>i</i>Pr₂C₆H₃) have been synthesized and characterized. They catalyze the intermolecular hydrophosphination of alkenes, dienes, and alkynes with high activity and selectivity under mild conditions. Highly selective 1,4-additions (94–100%) for the conjugated dienes examined have been observed with both catalysts. The calcium complex exclusively catalyzes anti addition to alkynes, including terminal alkynes, while the ytterbium, in most cases, catalyzes syn addition. The calcium catalyst could promote hydrophosphination of hindered alkenes such as stilbene under relatively mild conditions

2‑Hydro-2-aminophosphasilene with N–Si–P π Conjugation

The first 2-aminophosphasilene, [Ar­(Me3Si)­N]­HSiPAr′ (4, Ar = 2,6-iPr2C6H3, Ar′ = 2,6-Mes2C6H3), bearing a hydride ligand on the three-coordinate silicon atom has been synthesized and structurally characterized. Both X-ray data of 4 and DFT calculations on the model compound (H2N)­HSiPH (4′) disclosed that the amino group on the silicon atom results in significant N–Si–P π conjugation

2‑Hydro-2-aminophosphasilene with N–Si–P π Conjugation

The first 2-aminophosphasilene, [Ar­(Me3Si)­N]­HSiPAr′ (4, Ar = 2,6-iPr2C6H3, Ar′ = 2,6-Mes2C6H3), bearing a hydride ligand on the three-coordinate silicon atom has been synthesized and structurally characterized. Both X-ray data of 4 and DFT calculations on the model compound (H2N)­HSiPH (4′) disclosed that the amino group on the silicon atom results in significant N–Si–P π conjugation

2‑Hydro-2-aminophosphasilene with N–Si–P π Conjugation

The first 2-aminophosphasilene, [Ar­(Me₃Si)­N]­HSiPAr′ (<b>4</b>, Ar = 2,6-<i>i</i>Pr₂C₆H₃, Ar′ = 2,6-Mes₂C₆H₃), bearing a hydride ligand on the three-coordinate silicon atom has been synthesized and structurally characterized. Both X-ray data of <b>4</b> and DFT calculations on the model compound (H₂N)­HSiPH (<b>4′</b>) disclosed that the amino group on the silicon atom results in significant N–Si–P π conjugation

Synthesis and Reactions of Aluminum Sulfonamide Alkyls and Hydride

Aluminum compounds supported by a sulfonamide ligand are described. Reaction of AlEt3 with 1 equiv of the sulfonyl amine ArNH(SO2-p-Tol) (Ar = 2,6-iPr2C6H3, Tol = 4-MeC6H4) yielded the dimeric aluminum species [ArN(SO2-p-Tol)AlEt2]2 (1), and reactions of AlEt3 and AlH3·NMe3 with 2 equiv of ArNH(SO2-p-Tol) yielded the aluminum bis(sulfonamide) species [ArN(SO2-p-Tol)]2AlEt (2) and [ArN(SO2-p-Tol)]2AlH (3). The iodide species [ArN(SO2-p-Tol)AlI2]2 (4) and [ArN(SO2-p-Tol)]2AlI (5) were prepared by the reaction of 1 and 2 with iodine. Reaction of 3 with PhNH2, HCCPh, and Ph2CO yielded [ArN(SO2-p-Tol)]2AlNHPh (6), [ArN(SO2-p-Tol)]2AlCCPh (7), and [ArN(SO2-p-Tol)]2AlOCHPh2 (8). Treatment of 6 with BunLi in n-hexane led to a ligand transfer reaction to give the dimeric lithium salt [ArN(SO2-p-Tol)Li(THF)2]2 (9). Compounds 1−4 and 7−9 have been characterized by X-ray single-crystal analysis, which disclosed that the aluminum mono(sulfonamide) compounds adopt a dimeric NSOAlNSOAl eight-membered-ring structure while the aluminum bis(sulfonamide) species are monomeric species with a five-coordinate aluminum center. Interestingly, the lithium salt 9 has a dimeric structure with an OSOLiOSOLi eight-membered-ring core. Compounds 3 and 8 are found to be active for lactide polymerization at high temperature