Beiträge zur Chemie des Phosphors. 129. Synthese und Eigenschaften der Phospha-germa-cyclobutane (t-BuP)2(GePh2)2 und (t-BuP)3GePh2

Contributions to the Chemistry of Phosphorus. 129. Synthesis and Properties of the Phospha-germa-cyclobutanes (t-BuP)₂(GePh₂)₂ and (t-BuP)₃GePh₂ The phospha-germa-cyclobutanes 1,2-di-tert-butyl-3,3,4,4-tetraphenyl-1,2-diphospha-3,4-digerma-cyclob utane, (t-BuP)₂(GePh₂)₂ ( 1 ), and 1,2,3-tri-tert-butyl-4,4-diphenyl-1,2,3-tri-phospha-4-germa-cyclobutan e, (t-BuP)₃GePh₂ ( 2 ), are obtained as main-products of the cyclocondensation of K(t-Bu)P? P(t-Bu)K with Ph₂GeCl₂ under certain reaction conditions. 1 and 2 could be isolated in the pure state and were clearly characterized as the first four-membered P₂Ge₂ and P₃Ge heterocycles, respectively.     

Beiträge zur Strukturchemie phosphorhaltiger Ketten und Ringe. 7. Die Kristall- und Molekülstruktur des Diphosphagermetans (t-BuP)2(GePh2)2

Structural Chemistry of Phosphorus Containing Chains and Rings. 7. Molecular and Crystal Structure of the Diphosphagermetane (t-BuP)₂(GePh₂)₂ The compound 1,2-di-tert-butyl-3,3,4,4-tetraphenyl-diphospha-3,4-digerma-cyclobutan, (t-BuP)₂(GePh₂)₂, crystallizes monoclinically in the space group P2₁/c with a = 996.8 pm, b = 1337.3 pm, c = 2403.4 pm, β = 92.66° and Z = 4 formula units. The main structural feature is a non-planar four-membered ring. The (average) bond lengths are d(Ge? Ge) = 242.1 pm, d(Ge? P) = 234.0 pm, d(P? P) = 221.6 pm, d(Ge? C) = 194.9 pm, d(P? C) = 188.tyl4 pm, d(C? C)_Ph = 136.l5 pm, d(C? C)_t-Bu = 151.8 pm, d(C? H)_Ph = 91 pm, d(C? H)_t-Bu ? 95 pm. The geometry of the substituents phenyl and tert-butyl is quite normal.     

Beiträge zur Chemie des Phosphors. 101. Synthese und Eigenschaften von Diphosphaboriranen (t-BuP)2BNR2 und (t-BuP)2BNR1R2

Contributions to the Chemistry of Phosphorus. 101 Synthesis and Properties of Diphosphaboriranes (t-BuP)₂BNR₂ and (t-BuP)₂BNR¹R² The reaction of K(t-Bu)P? P(t-Bu)K with diorganylaminodichloroboranes under suitable conditions leads to the new 1,2-di-tert-butyl-3-diorganylamino-1,2,3-diphosphaboriranes (-1,2-diphospha-3-boracyclopropanes) (t-BuP)₂BNR₂ ( 2 , 7 ) and (t-BuP)₂BNR¹R² ( 3 — 6 ), respectively. The P₂B three-membered heterocycles 2 — 5 can be isolated in good yields. They are relatively stable against dimerization to the corresponding phosphorus boron six-membered ring compounds with opposite boron atoms. The rate of dimerization depends on steric and electronic influences of the substituents at the three-membered ring. All NMR spectroscopic results are only consistent with a structure in which the B and N atoms show planar coordination and are connected by a partial double bond.     

Beiträge zur Chemie des Phosphors. 144. Synthese und Eigenschaften des Hexaphospha-3-germaspiro[2.4]heptans (t-BuP)2Ge(t-BuP)4

Contributions to the Chemistry of Phosphorus. 144. Synthesis and Properties of the Hexaphospha-3-germaspiro[2.4]heptane (t-BuP)₂Ge(t-BuP)₄ The cyclocondensation of K(t-Bu)P? P(t-Bu)K with germanium tetrachloride in the molar ratio of 2:1 yields the novel spirocyclic compound 1,2,4,5,6,7-hexa-tert-butyl-1,2,4,5,6,7-hexaphospha-3-germaspiro[2.4]heptane, (t-BuP)₂Ge(t-BuP)₄ ( 1 ). Besides considerable amounts of (t-BuP)₄ are formed and occasionally some (t-BuP)₃ can be found. 1 could be isolated in the pure state and has been NMR-spectroscopically characterized as a spirocyclic compound with a P₂GeP₄ skeleton.     

Beiträge zur Chemie des Phosphors. 106. Synthese und Eigenschaften des Diphosphacyclopropans (t-BuP)2CHMe

Contributions to the Chemistry of Phosphorus. 106. Synthesis and Properties of the Diphosphacyclopropane (t-BuP)₂CHMe The new 1,2-di-tert-butyl-3-methyl-1,2-diphosphacyclopropane (1,2-di-tert-butyl-3-methyl-diphosphirane), (t-BuP)₂CHMe ( 1 ), is obtained by reacting K(t-Bu)P? P(t-Bu)K with 1,1-dichloroethane under suitable conditions. 1 can be isolated by high vacuum distillation and is stable for months when stored under inert gas at room temperature. Particularly, no dimerization to the corresponding 1,2,4,5-tetraphosphacyclohexane takes place. The NMR parameters indicate an increase of the exocyclic bond angles compared to (t-BuP)₂CH₂. The signs of all CP coupling constants have been determined by spin tickling experiments. The ²J(CCP)-coupling of the methyl group at the ring carbon depends strongly on the dihedral angle.     

Beiträge zur Chemie des Phosphors. 128. Synthese des Diphosphastanna-cyclopropans (t-BuP)2Sn(t-Bu)2

Contributions to the Chemistry of Phosphorus. 128. Synthesis of the Diphosphastanna-cyclopropane (t-BuP)₂Sn(t-Bu)₂ The first three-membered P₂Sn heterocycle, 1,2,3,3-tetra-tert-butyl-1,2,3-diphosphastanna-cyclopropane (1,2,3,3-tetra-tert-butyl-1,2,3-diphosphastannirane) ( 1 ), has been synthesized by [2+1] cyclocondensation of K(t-Bu)P—P(t-Bu)K with (t-Bu)₂SnCl₂. 1 is stable at room temperature. Besides, (t-BuP)₂[Sn(t-Bu)₂]₂ ( 2 ), (t-BuP)₄Sn(t-Bu)₂ ( 3 ), and (t-BuP)₄ are formed. In the reaction with Et₂SnCl₂, the six-membered ring compound [(t-BuP)₂SnEt₂]₂ ( 4 ) is the main-product; the four- and five-membered cyclostannaphosphanes (t-BuP)₃SnEt₂ ( 5 ) and (t-BuP)₃(SnEt₂)₂ ( 6 ) are also formed. 1 could be isolated in the pure state and has been unambiguously characterized as a three-membered heterocycle with a P₂Sn skeleton. The ³¹P-NMR parameters of the other new cyclostannaphosphanes 2–6 are reported.     

Beiträge zur Chemie des Phosphors. 160. Zur Ringspaltung der Phosphor-Dreiringheterocyclen (t-BuP)2CMe2 und (t-BuP)2N(i-Pr) mit Kalium bzw. K-Naphthalid

Contributions to the Chemistry of Phosphorus. 160. About the Ring Cleavage of the Phosphorus Three-Membered Heterocycles (t-BuP)₂CMe₂ and (t-BuP)₂N(i-Pr) with Potassium or K-Naphthalenide The reaction of (t-BuP)₂CMe₂ with potassium or K-naphthalenide in tetrahydrofuran or 1,2-dimethoxyethane mainly leads to the symmetric phosphide K(t-Bu)P? ;CMe₂? ;P(t-Bu)K ( 1 ) via P? ;P-bond cleavage. Above —78°C 1 decomposes into the monophosphides KHP(t-Bu) ( 3 ) and KP(t-Bu)(i-Pr) ( 4 ). In the case of (t-BuP)₂N(i-Pr) under analogous conditions essentially the P? ;N-bond is split up yielding the phosphide K(t-Bu)P? ;P(t-Bu)? ;NH(i-Pr) ( 5 ), which is stable at room temperature. Contrary to (t-BuP)₂BN(i-Pr)₂ cyclic phosphides are not formed. The different reactive behavior in the metalation of phosphorus three-membered heterocycles of the type (PR¹)₂ER (E = hetero atom) is discussed.     

Beiträge zur Chemie des Phosphors. 138. P5(t-Bu)4H – das erste Derivat von iso-P5H5

Contributions to the Chemistry of Phosphorus. 138. P₅(t-Bu)₄H — the First Derivative of iso-P₅H₅ The thermolysis of 1,2-di-tert-butyldiphosphane, H(t-Bu)P? P(t-Bu)H, yields under suitable conditions the compound P₅(t-Bu)₄H ( 1 ) as the main product. Besides, the tert-butylphosphanes t-BuPH₂, P₆(t-Bu)₅H ( 2 ), H₂(t-BuP)₃, and (t-BuP)₄ are formed. 1 has been isolated in the pure state and structurally characterized as 1-(tert-butylphosphino)-2,3,4-tri-tert-butyl-cyclotetraphosphane. Hence, compound 1 is a derivative of iso-P₅H₅ with a branched phosphorus skeleton built up by a four-membered ring and a phosphorus side chain.     

Beiträge zur Chemie des Phosphors. 142. P6(t-Bu)5H – das erste Cyclotetraphosphan mit P2-Seitenkette

Contributions to the Chemistry of Phosphorus. 142. P₆(t-Bu)₅H – the First Cyclotetraphosphane with a P₂ Side Chain The thermolysis of 1, 2-di-tert-butyldiphosphane, H(t-Bu)P? P(t-Bu)H, leads to formation of the hitherto unknown hexaphosphane P₆(t-Bu)₅H ( 1 ). In the first instance the iso-P₅H₅ derivative P₅(t-Bu)₄H [3] is formed, which reacts further with H₂(t-BuP)₂ or H₂(t-BuP)₃ yielding 1 . Compound 1 has been isolated in the pure state and structurally characterized as 1-(1,2-di-tert-butyldiphosphino)-2, 3, 4-tri-tert-butyl-cyclotetraphosphane, i. e. as a four-membered ring compound with a P₂ side chain. Due to the chirality of the P atoms in the side chain, 1 exists as a mixture of two configurational isomers, the threo-and the erythro-form.     

Beiträge zur Chemie des Phosphors. 224. Zur Thermolyse von 1,2-Di-tert-butyldiphosphan, 1,2,3-Tri-tert-butyltriphosphan und Tetra-tert-butylcyclotetraphosphan

Contributions to the Chemistry of Phosphorus. 224. On the Thermolysis of 1,2-Di-tert-butyldiphosphane, 1,2,3-Tri-tert-butyltriphosphane, and Tetra-tert-butylcyclotetraphosphane On disproportionation of 1,2-di-tert-butyldiphosphane, H(t-Bu)P? P(t-Bu)H (1) , 1,2,3-tri-tert-butyltriphosphane, H₂(t-BuP)₃ (2) , is formed which reacts further at temperatures above 100°C to give 1-(tert-butylphosphino)-2,3,4-tri-tert-butylcyclotetraphosphan, P₅(t-Bu)₄H (4) . Compound 4 reacts with 1 or 2 with lengthening of the P-sidechain to furnish the corresponding 1-(1,2-di-tert-butyldiphosphino)-2,3,4-tri-tert-butylcyclotetraphosphane, P₆(t-Bu)₅H (5) . At temperatures above 170°C, 5 disproportionates into the tetra-tert-butylcyclotetraphosphane, (t-BuP)₄ (3) which is stable up to about 200°C, and the bicyclo[3.1.0]hexaphosphane P₆(t-Bu)₄ from which the polycyclophosphanes P₉(t-Bu)₃ and P₈(t-Bu)₆ arise during the further course of the thermolysis. These products are finally converted through even more phosphorus-rich and more highly condensed t-butylcyclophosphanes into elemental phosphorus. In each reaction step, varying amounts of the monophosphane derivatives t-BuPH₂, (t-Bu)₂PH, and (t-Bu)₃P are formed. The proposed course of the reaction is further substantiated by the pyrolysis products of pure 2 and 3 .     

Beiträge zur Chemie des Phosphors. Synthese und Eigenschaften des 1,2-Diphospha-3,4-diboretans (t-BuP)2(BNMe2)2

Contributions tot he Chemistry of Phosphorus. 148. Synthesis and Properties of the 1,2-Diphospha-3,4-diboretane (t-BuP)₂(BNMe₂)₂ The first 1, 2-diphospha-3,4-diboretane (1,2-diphospha-3, 4-diboracyclobutane) (t-BuP)₂(BNMe₂)(1) was prepared by [2+2] cyclocondensation of K(t-Bu)P? P(t-Bu)K with Cl(Me₂N)B? B(NMe₂)Cl. 1 could be isolated in the pure state and was NMR spectroscopically characterized as a compound with a planar P₂ B₂ ring skeleton.     

Beiträge zur Strukturchemie phosphorhaltiger Ketten und Ringe. 1. Die KristallStruktur des Diphosphasilirans (t-BuP)2SiPh2

Structural Chemistry of Phosphorus-containing Chains and Rings. 1. Crystal Structure of the Diphosphasilirane (t-BuP)₂SiPh₂ The three-membered P₂Si-heterocycle 1, 2-di-tert-butyl-3, 3-diphenyl-1, 2, 3-diphosphasilirane (t-BuP)₂SiPh₂ crystallizes monoclinic in the space group P2₁ with a = 1041.2 pm, b = 882.3 pm, c = 1158.1 pm, β = 91.33° and Z = 2 formula units. A special structural feature is the regular triangle built up by two P and one Si. Therefore the endocyclic bond angle at Si is as low as 60°. The average bond lengths are P? P = 222.6 pm, P? Si = 222.5 pm, P? C = 190.8 pm, Si? C = 186.6 pm, (C? C )ph = 139.0 pm, ( C? C )_t-Bu = 151.7 pm. The geometry of the substituents phenyl and tert-butyl is quite normal, the last ones are slightly disordered.     

Beiträge zur Strukturchemie phosphorhaltiger Ketten und Ringe. 2. Die Kristall- und Molekülstruktur des Diphosphaborirans (t-BuP)2BNEt2

Structural Chemistry of Phosphorus-containing Chains and Rings. 2. Crystal and Molecular Structure of the Diphosphaborirane (t-BuP)₂BNEt₂ The three-membered P₂B-heterocycles 1,2-di-tert-butyl-3-diethylamino-1,2,3-diphosphaborirane, (t-BuP)₂BNEt₂, crystallizes triclinic in the space group P1 with a = 935.5 pm, b = 985.4 pm, c = 987.4 pm,α = 81.55°, β = 89.40°, γ =69.07°, and Z = 2 formula units. The main structural feature is a short B? N-bond length (138.2 pm) inside a plane P₂BN-group. The endocyclic bond angles are 54.0° on phosphorus and 72.0° on boron. The (average) bond lengths are P? P = 222.5 pm, P? C = 189.5 pm, P? B = 189.3 pm, B? N = 138.2 pm, N? C = 147.2 pm, C? C = 152.6 pm, and C? H = 98 pm. The geometry of the substituents ethyl and tert-butyl is quite normal.     

Beiträge zur Chemie des Phosphors. 104. Synthese und Eigenschaften von 1,3-Dihalogen-1,2,3-tritert-butyltriphosphanen (t-BuP)3X2, X = Cl,Br, I

Contributions to the Chemistry of Phosphorus. 104. Synthesis and Properties of 1,3-Dihalogen-1,2,3-tri-tert-butyltriphosphanes (t-BuP)₃X₂, X = Cl, Br, I The halogenating ring-cleavage of tri-tert-butyl-cyclotriphosphane, (t-BuP)₃, by iodine, bromine or phosphorus(V)bromide as well as phosphorus(V)chloride leads to the first 1,3-dihalogen-1,2,3-triorganyltriphosphanes (t-BuP)₃I₂ ( 1 ), (t-BuP)₃Br₂ ( 2 ), and (t-BuP)₃Cl₂ ( 3 ). The 1,2-dihalogen-1,2-di-tert-butyldiphosphanes (t-BuP)₂I₂ ( 4 ), (t-BuP)₂Br₂ ( 6 ), and (t-BuP)₂Cl₂ ( 9 ) as well as the dihalogen-tert-butylphosphanes t-BuPI₂ ( 5 ), t-BuPBr₂ ( 7 ), and t-BuPCl₂ ( 10 ) are formed as by-products. Moreover, the reaction of (t-BuP)₃ with PBr₅ leads to 1-bromo-2,3,4-tri-tert-butyl-cyclo-tetraphosphane, (t-BuP)₃(PBr) ( 8 ). The compounds 1 and 3 could be isolated in a pure state and were characterized in all details. 3 is a reMarkably stable open-chain triphosphane.     

Beiträge zur Chemie des Phosphors. 134. Über die Triphosphane H(t-BuP)3H,Li(t-BuP)3Li und Me3Si(t-BuP)3SiMe3

Contributions to the Chemistry of Phosphorus. 134. On the Triphosphanes H(t-BuP)₃H' Li(t-BuP)₃Li, and Me₃Si(t-BuP)₃SiMe₃ The reaction of 1,3-diiodo-1,2,3-tri-tert-butyltriphosphane, I(t-BuP)₃I, with lithium aluminium hydride leads to 1,2,3-tri-tert-butyltriphosphane, H(t-BuP)₃H ( 1 ). 1 reacts with n-butyllithium to 1,3-dilithium-1,2,3-tri-tert-butyltriphosphide, Li(t-BuP)₃Li ( 2 ), which reacts further with trimethylchlorosilane yielding 1,3-bis(trimethylsilyl)-1,2,3-tri-tert-butyltriphosphane, Me₃Si(t-BuP)₃SiMe₃ ( 3 ). The triphosphanes 1, 2 and 3 could be isolated in a pure state. In solution 1 forms the threo, threo and the threo,erythro configurated diastereomers 1a and 1b in a ratio of about 2:1. 3 predominantly exists in form of the threo,erythro configurated diastereomer 3b by steric reasons.     

Beiträge zur Chemie des Phosphors. 152. Funktionalisierte Cyclotriphosphane des Typs (t-BuP)2PX (X = K,SiMe3, SnMe3, Cl,Br, PCl2, P(t-Bu)Cl,P(t-Bu)I)

Contributions to the Chemistry of Phosphorus. 152. Functionalized Cyclotriphosphanes of the Type (t-BuP)₂PX (X = K, SiMe₃, SnMe₃, Cl, Br, PCl₂, P(t-Bu)Cl, P(t-Bu)I) Functionalized cyclotriphosphanes of the type (t-BuP)₂PX with electropositive or electronegative substituents X have been prepared on various synthetic routes: KP(t-BuP)₂ ( 1 ) can be obtained in 50–55 per cent purity by reacting (t-BuP)₄ or (t-BuP)₃ with potassium. Reaction of 1 with Me₃SiCl or Me₃SnCl leads to the cyclotriphosphanes (t-BuP)₂PSiMe₃ ( 2 ) and (t-BuP)₂PSnMe₃ ( 3 ), respectively; the cyclocondensation of Cl(t-Bu)P? P(t-Bu)Cl with P(SnMe₃)₃, however, is more convenient for the preparation of 3 . In a similar way the halogenated compounds (t-BuP)₂PCl ( 4 ) and (t-BuP)₂PBr ( 5 ) can be obtained from Me₃Sn(t-Bu)P? P(t-Bu)SnMe₃ ( 6 ) and PX₃ (X = Cl, Br). The phosphino-substituted cyclotriphosphanes (t-BuP)₂P? PCl₂ ( 7 ), (t-BuP)₂P? P(t-Bu)Cl ( 8 ), and (t-BuP)₂P? P(t-Bu)I ( 9 ) are accessible by the reaction of 3 with PCl₃ and t-BuPX₂ (X = Cl, I), respectively. 2–9 could be obtained free from phosphorus-containing by-products and were ³¹P-NMR spectroscopically characterized as compounds with a cyclic P₃ skeleton.     

Beiträge zur Chemie des Phosphors. 136 [1]. 31P-Kernresonanzspektren und Struktur der 1,3-Dihalogen-1,2,3-tri-tert-butyltriphosphane X(t-BuP)3X,X = Cl,Br, I

Contributions to the Chemistry of Phosphorus. 136. ³¹P-N.M.R. Spectra and Structure of 1,3-Dihalogen-1,2,3-tri-tert-butyltriphosphanes X(t-BuP)₃X, X = Cl, Br, I The 1,3-dihalogen-1,2,3-tri-tert-butyltriphosphanes (t-BuP)₃Cl₂ ( 1 ), (t-BuP)₃Br₂ ( 2 ), and (t-BuP)₃I₂ ( 3 ), which are formed in the halogenating ring cleavage of tri-tert-butyl-cyclotriphosphane, (t-BuP)₃, by halogens or halogen compounds, favour the erythro, threo configuration by steric reasons. However, the erythro, erythro configurated diastereomer, whose stability depends on the size of the halogen substituents and on the rate of inversion at the phosphorus atoms, is formed initially. The reaction of the erythro, erythro and erythro, threo configurated diastereomers of 1–3 with lithium aluminium hydride leads stereospecifically to the threo, threo and threo, erythro configurated diastereomers of 1,2,3-tri-tert-butyltriphosphane, H₂(t-BuP)₃ ( 4 ), respectively.     

Beiträge zur Chemie des Phosphors. 159. Über die Reaktion des Diphosphaborirans (t-BuP)2BN(i-Pr)2 mit Kalium bzw. Kaliumnaphthalid

Contributions to the Chemistry of Phosphorus. 159. On the Reaction of the Diphosphaborirane (t-BuP)₂BN(i-Pr)₂ with Potassium or Potassium Naphthalenide The reaction of (t-BuP)₂BN(i-Pr)₂ with potassium or K-naphthalenide in tetrahydrofuran leads to K(t-Bu)P? ;BN(i-Pr)₂? P(t-Bu)K ( 1 ) via P? ;P bond cleavage of the three-membered ring skeleton. Above ? 78°C 1 changes into the asymmetric compound K(t-Bu)P? ;P(t-Bu)? BHN(i-Pr)₂ ( 2 ). In dimethoxyethane additionally the monometallated diphosphaborirane K(t-Bu)P₂BN(i-Pr)₂ ( 3 ) is formed. 1 and 3 , which could be isolated free from other phosphorus containing compounds, as well as the corresponding silylphosphanes Me₃Si(t-Bu)P? ;BN(i-Pr)₂? ;P(t-Bu)SiMe ₃ ( 4 ) and Me₃Si(t-Bu)P₂BN(i-Pr)₂ ( 5 ) were characterized by NMR spectroscopy. Protolysis of 3 or 5 leads to a decomposition of the three-membered ring skeleton with formation of H(t-Bu)P? ;PH₂.     

Synthesis and X-ray single crystal structure of first aromatic ortho-di-tert-butyl azolo[1,2,4]triazine

Oxidation of 3,4-di-tert-butyl-8-methyl-1,4-dihydropyrazolo[5,1-c][1,2,4]triazine with NBS/K₂CO₃ furnished 3,4-di-tert-butyl-8-methylpyrazolo[5,1-c][1,2,4]triazine, a mildly strained heteroaromatic compound. X-Ray single crystal diffraction analysis indicated that the conjugated 1,2,4-triazine ring adopts a twist-boat configuration, while the two t-Bu substituents are located on the opposite sides of the azole plane. The related 3-tert-butyl-4-(o-C-carboranyl)-8-methyl-1,4-dihydropyrazolo[5,1-c][1,2,4]triazine was also synthesized, however, its oxidative aromatization was unsuccessful.     

Beiträge zur Chemie des Phosphors. 111. 1,2-Dichlor-1,2-di-tert-butyldiphosphan

Contributions to the Chemistry of Phosphorus. 111. 1,2-Dichloro-1,2-di-tert-butyl-diphosphane The reaction of tri-tert-butyl-cyclotriphosphane, (t-BuP)₃, with phosphorus(V) chloride (molar ratio 1:2) leads to the title compound Cl(t-Bu)P? P(t-Bu)Cl ( 1 ), which is remarkably stable against disproportionation reactions. As the first 1,2-dichloro-1,2-diorganyldiphosphane, 1 has been isolated in a pure state and was thoroughly characterized. At room temperature, 1 exists in a mixture of the d,l and meso form (about 20:80). The mutual repulsion of the negative polarized Cl atoms and their preferred gauche arrangement to the free electron pairs of neighboured P atoms leads to a gauche-conformation of the lone electron pairs in the d,l- and to a trans-conformation in the meso-configuration.