Phenylboration of Monoalkyn-1-yltin Compounds

2007 ◽  
Vol 62 (12) ◽  
pp. 1509-1513 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Oleg L. Tok ◽  
Wolfgang Milius

The 1 : 1 reactions of triphenylborane 1 with monoalkyn-1-yltin compounds Me3Sn-C≡C-R1 2 [R1 = tBu (a), Ph (b), ferrocenyl (c), Si(H)Me2 (d), SnMe3 (e)] afford mainly (> 80 %) the corresponding alkene derivatives 3 by 1,1-phenylboration. Exchange B-Ph/Sn-C≡C-R1 takes place as a side reaction. The corresponding 1 : 2 reaction with 2b leads to the dialkenylborane 4b (R1 = Ph), of which the molecular structure could be determined by X-ray analysis. In contrast, the 1 : 2 reaction with 2e gave an allene derivative 5e. The solution-state structures of compounds 3 - 5 have been confirmed by 1H, 11B, 13C and 119Sn NMR spectroscopy.

2009 ◽  
Vol 64 (4) ◽  
pp. 399-402 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Christoph Bihlmayer ◽  
Khadija Shahid ◽  
Wolfgang Milius

Trimethyl- and triethyl(propyn-1-yl)tin react with 9-borabicyclo[3.3.1.]nonane (9-BBN) mainly by exchange of the propynyl group against hydrogen, accompanied by numerous side reaction. This is in contrast to the findings for other alkynyltin compounds bearing a second bulky substituent at the C≡C bond. The exchange product, 9-propyn-1-yl-9-borabicyclo[3.3.1]nonane, was isolated as its crystalline pyridine adduct and fully characterised by NMR spectroscopy in solution and X-ray structural analysis in the solid state.


Author(s):  
Rosa María Claramunt ◽  
María Dolores Santa María ◽  
Isabelle Forfar ◽  
Francisco Aguilar-Parrilla ◽  
María Minguet-Bonvehí ◽  
...  

1986 ◽  
Vol 41 (6) ◽  
pp. 722-730 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Eduard Michels ◽  
Jürgen Kaub

11-Isopropylidene-bicyclo[4.4.1]undeca-2,4,8-triene (IBU, 1A) and five alkyl substituted de­rivatives (1B-1F) contain a conjugated diene unit and two isolated CC-double bonds, one exocyclic and one incorporated into the bicvclus, each suited for complexation to transition metals. With [Cr(CO)3(CH3CN)3] (2) 1A-1F form [Cr(CO)3(η6-IBU)] complexes (3A−3F). in which the IBU ligands are coordinated to the chromium via the diene unit and the exocyclic CC-double bond. The corresponding [Mo(CO)3(η6-IBU)] complexes (5A−5F) are obtained from the reactions of [Mo(CO)3(diglyme)] (4) with 1A−1F. In addition, the isomeric [Mo(CO)3(η6-IBU)] complexes (6A−6D) are formed, in which the IBU ligands are bound to molybdenum via the three cyclic CC-double bonds. The complexes 3A−3F, 5A−5F and 6A−6D were studied by IR and NMR spectroscopy (1H. 13C) and characterized by C, H elemental analyses. The crystal and molecular structure of 1A was determined by X-ray structure analysis.


2008 ◽  
Vol 63 (3) ◽  
pp. 275-279 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Ezzat Khan ◽  
Rhett Kempe

Protodeborylation of triorganoboranes, usually carried out under mild reaction conditions using an excess of acetic acid, affords 1,5-dialkyl-3,7-dimethyl-4,8,9-trioxa-2,6-dioxonia-1,5-diboratabicyclo [3.3.1]nona-2,6-dienes OB(R)OC(Me)OB(R)OC(Me)O [1 (R = Et), 2 (R = cyclooctyl)]. Acetoxy(dialkyl) boranes and di(acetoxy)alkylboranes were not formed in an appreciable amount. Compounds 1 and 2 were characterized by NMR spectroscopy (1H, 11B, 13C NMR) in solution, the molecular structure of 2 was determined by X-ray analysis. The gas-phase geometry of 1 was optimized by calculations [B3LYP/6-311+G(d, p) level of theory], and its NMR parameters were also calculated at the same level of theory.


2000 ◽  
Vol 55 (7) ◽  
pp. 576-582 ◽  
Author(s):  
Katerina E. Gubina ◽  
Vladimir A. Ovchynnikov ◽  
Vladimir M. Amirkhanov ◽  
Helmut Fischer ◽  
Rüdiger Stumpf ◽  
...  

Abstract The coordination compounds of the general formula Ln(HL)2(NO3)3, (where Ln = La - Eu (without Pm), HL = C6H5C(O)NHP(O)[N(CH3)2]2, N,Nʹ-tetramethyl-Nʺ-benzovlphosphoryl-triamide) have been synthesized and characterized by means of IR, UV-VIS, 1H, 31P NMR spectroscopy, and X-ray analysis. The complexes are isostructural according to X-ray powder diffraction studies. The crystal structure of the cerium(lll) complex has been determined. Crystal data: monoclinic, P21/c, with a = 10.503(9), b = 15.62(2), c = 21.91(2) Å, β = 99.56(8)°, Z = 4, V = 3546(6) Å3, R1= 0.0550, wR2 = 0.1383 for 6970 unique reflections used. The complex has a molecular structure. Neutral phosphoryltriamide ligands are coordinated to the metal ion in a bidentate manner via phosphoryl and carbonyl oxygen atoms with formation of six membered chelate rings. The coordination polyhedron of the Ce atom is a sphenocorona; C.N. = 10 (4 O[HL] + 6 O [NO3-]).


2001 ◽  
Vol 56 (11) ◽  
pp. 1100-1108 ◽  
Author(s):  
Fritz Preuss ◽  
Monika Vogel ◽  
Uwe Fischbeck ◽  
Jens Pemer ◽  
Gerhard Overhoff ◽  
...  

The reactions of tBuN = VCl2 · DME with LiX (X = NHtBu, NR2, OSiPh3, SR, Alkyl, Cp) have been studied. LiNHtBu and LiCH3 furnish the binuclear diamagnetic tert-butylimido-vanadium( IV) compounds [(μ-NtBu)2V2X4]; in all other cases only the vanadium(V) compounds tBuN=VX3 and tBuN=VCpCl2 formed by disproportionation reactions of vanadium(IV) can be isolated. The syntheses of various mononuclear amido tert-butylimido-vanadium(V) complexes as well as of the binuclear complexes [μ-NtBu)2V2(NtBu)2Cl2] and [(μ-0)V2(NtBu)2Cp2Cl2] are also described. All compounds obtained have been characterized by 51V NMR spectroscopy. tBuN=V(OMe)3 was investigated by X-ray diffraction analysis; the molecular structure has been found to be that of a binuclear vanadium(V) complex with two bridging methoxo ligands.


1991 ◽  
Vol 46 (6) ◽  
pp. 714-718 ◽  
Author(s):  
Lothar Weber ◽  
Uwe Sonnenberg ◽  
H. G. Stammler ◽  
Beate Neumann

The dichlorophosphido complexes (η5-C5Me5)(CO)2M–PCl2 (2a: M = Fe; 2 c: M = Ru) react with two equivalents of Ph2C=NSiMe3 to yield the first η1-2,4-diaza-3-phosphapenta-1,4-dien-3-yl complexes (4a,c). Intermediates (η5-C5Me5)(CO)2M–P(Cl)(N=CPh2) (3a,c) are detected by 31P{1H} NMR spectroscopy, the preparation of pure 3a, however, failed. The products 4a, c have been characterized by elemental analysis as well as spectroscopic data (IR, 1H, 13C, 31P NMR, MS). The molecular structure of 4a has been elucidated by single X-ray analysis.


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