Silicon-phosphorus rings

Unlike cyclic silicon-phosphorus compounds, which occur as dimers and/or trimers, the cyclic silicon-arsenic ring of (Me2SiAsMe)4 is eight-membered. It results from MeAsHLi and Me2SiCl2 along with polymer, and occurs in solution as a mixture of conformers (equation 90)no. 

Silicon-phosphorus heterocyclic structures (rings, cages, polycyclic ladders) are also well investigated. ... 

Ruthenocene also forms the bridge structure of two cyclopentadienyl rings the chain element is not only a carbon chain (Scheme 16.3) but also silicon, phosphorus and palladium atom [32a,32b]. 

Riegel B, Pfitzner A, Heckmann G, Pluck E, Binder H (1994) Phosphorus-boron and phosphorus-silicon ring systems functionalization of phosphorus ring systems. Phosphorus Sulfur Silicon 93-94 173-176... 

Unsolvated organomagnesium compounds have been recommended for the synthesis of organometallic derivatives of mercury, boron, aluminum, silicon, germanium, tin, phosphorus, arsenic, and antimony6-8 and have been used in procedures for the alkylation of aromatic rings and for the production of various polymerization catalysts.4 9... 

Paritosh, D. R. et al Chem. Abs., 1994, 121, 35869j U.S. Pat. Appl. 42,229 Paritosh, D. R. etal., Phosphorus, Sulfur, Silicon Relat. Elem., 1994, 90(1-4), 175 This and several other compounds with fewer nitro groups and partial replacement of the spiro rings by halogen are patented as explosives. 

Addition of elemental chalcogens to the double bonds between silicon and phosphorus gives three-membered ring compounds (Scheme 9).59 A 1,2-di-bromodigermene reacts with S8 to give the four-membered ring compound,60 in... 

Several reports have been made of a successful catalyzed addition/ substitution reaction resulting in direct attachment of phosphorus to aromatic rings. The preparation of mixed triarylphosphines has been accomplished by the reaction of tin- or silicon-substituted diphe-nylphosphines with aryl halides catalyzed by palladium reagents.74 A similar transformation has also been reported using nickel catalysis.75 The addition/substitution of diphenylphosphine to triflate functionalized phenolic linkages has been of use for the preparation of substances as analogues of tyrosine-related amino acid derivatives, accomplished with catalysis by palladium acetate (Equation 4.29).76... 

The [5,5]-fused bicyclic ring system with one fusion nitrogen atom and three additional heteroatoms in a 2 1 distribution over both ffve-membered rings (2N1) is the origin of a great number of structures. The additional heteroatoms are mainly nitrogen, oxygen, or sulfur, and less commonly phosphorus or silicon atoms. 

Synthesis of Fused Ring Systems with Phosphorus and Silicon Ring Atoms 842... 

Two phosphorus-containing ring systems and one silicon-containing fused heterocycle belonging to the hetero-atomic arrangements of this chapter have been synthesized recently. The synthetic pathways are presented in Scheme 25. 

Electrophilic attack at ring silicon, sulfur, selenium, and phosphorus Nucleophilic attack at ring silicon Nucleophilic attack at ring boron... 

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