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Norbornadiene
About: Norbornadiene is a research topic. Over the lifetime, 2389 publications have been published within this topic receiving 38603 citations.
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01 Jan 1973
TL;DR: Pillbury et al. as mentioned in this paper studied the nickel-promoted dimerization of norbornadiene (NBD) from three aspects; stereochemical and electronic factors in the substrate and the influence of ligands bound to the nickel which are not directly involved in the reaction.
Abstract: To gain a better understanding of metal promoted cycloaddition reactions, the nickel promoted dimerization of norbornadiene (NBD) was examined from three aspects; stereochemical and electronic factors in the substrate and the influence of ligands bound to the nickel which are not directly involved in the reaction. As an example of stereochemical perturbation, the 7-methyl derivative of NBD was dimerized using bis(tri-phenylphosphine)dicarbonylnickel, Ni(CO)2(P03)2 , as a promoter with both thermal and photochemical activation. It was found by an analysis of the nuclear magnetic resonance'spectra of the dimers that both 2+2 and 2+2+2 cyclodimerization products were produced. The major dimers had the same skeletal stereochemical configurations as the dimers produced from the corresponding thermal and photochemical reactions of NBD and to investigate substrate electronic factors, norbornene, pentacyclbtetradeca-5,11-diene (exo-trans-exo isomer) and [2,2,2]bicycloocta-2,5-diene were subjected, without success, to conditions found to produce dimers with NBD. A proposal describing the requisite electronic factors for active olefinic substrates was made. The influence of indirectly involved ligands was examined through a study of kinetics parameters in the thermal reaction of Ni(CO)2(P03)2 with NBD. The reaction was found to be very temperature sensitive, to be strongly inhibited by carbon monoxide and triphenylphosphine, and to exhibit an induction period followed by the major reaction period in which the rate of production of the two 2+2 dimers (both known) was constant. The kinetics results were viewed as the initial establishment of equilibrium between a number of competing reactions to produce very low steady state concentrations of active catalytic species. The substrate modification data and kinetics data were coordinated with the work of other investigators to give a unified picture of the nickel promoted cyclodimerization reaction. The use of electrochemical regeneration of active organometallic coupling reagents was also studied. It was found benzyl halides, bromo-benzene, benzoyl chloride, phenacyl bromide and n-hexyl bromide could be coupled with electro chemically produced metal species. The reactions were run in single compartment cells using N,N-dimethylformamide as solvent, a catalytic amount of a metal ion and stabilizing ligands such as triphenylphosphine to prevent zero valent metal from plating out. Carbonyl insertion and a unique formylation reaction were also studied. (Formula not captured by OCR) (Formula not captured by OCR) PART I: A STUDY OF STEREOCHEMICAL AND ELECTRONIC FACTORS IN THE NICKEL PROMOTED DIMERIZATION OF NORBORNADIENE PART II: ELECTRO-ORGANOMETALLIC CATALYSTS ■ by DALE GRANT PILLSBURY A thesis submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY
TL;DR: The tetracyclic phosphonium chloride (PCL) was synthesized by treatment of norbornadiene with CH3PCl2 at 65-80°C for one week as mentioned in this paper.
Abstract: The title compound which we1 and others2 have previously synthesized has now been extensively investigated. The tetracyclic phosphonium chloride 1 was prepared by treatment of norbornadiene with CH3PCl2 at 65–80°C for one week. Treatment of 1 with AICl3/CH2CI2 gave 2. Direct or “Inverse” addition at water to 2 dictated the stereochemistry of the oxide 3. Stereoassignments of 3 were made based on lanthanide shift −1H and 13C nmr studies studies. Extensive 2-D nmr studies (HETCOR, COSY) and triple irradiation experiments enabled chemical shift and coupling constant assignments.
TL;DR: In this article, a C2-symmetric norbornadiene derivative (1R,4R)-2,5-dibenzylbicyclo[2.2.1]hepta-diene was prepared and used for the rhodium-catalyzed asymmetric addition of organoboron and -tin reagents to α,β-unsaturated ketones, which gave high yields of the 1,4-addition products with up to 99% enantioselectivity.
Abstract: As a new type of chiral ligand, a C2-symmetric norbornadiene derivative (1R,4R)-2,5-dibenzylbicyclo[2.2.1]hepta-2,5-diene (1) was prepared and used for the rhodium-catalyzed asymmetric addition of organoboron and -tin reagents to α,β-unsaturated ketones, which gave high yields of the 1,4-addition products with up to 99% enantioselectivity.
TL;DR: In this article, the double bonds of the diolefines are not coordinated perpendicular to the P,Rh,P plane which is well-known in the case of the cycloocta-1,5-diene complex.
Abstract: C23H32BF4O3P2Rh, orthorhombic, P212121 (no. 19), a = 10.147(2) Å, b = 13.246(3) Å, c = 18.827(4) Å, V = 2530.5 Å, Z = 4, Rgt(F) = 0.025, wRref(F) = 0.067, T = 200 K. Source of material The synthesis is described in [1]. Discussion Unexpected differences between the title compound and the related cycloocta-1,5-diene (COD) complex [2] in the catalytic hydrogenation of the diolefines norborna-2,5-diene (NBD) and (Z,Z)-cycloocta-1,5-diene motivated us to determine the crystal structure of the title compound. The double bonds of the diolefines are not coordinated perpendicular to the P,Rh,P plane which is well-known. The dihedral angle between the planes P,Rh,P and X,Rh,X (X = centroid of the double bond) is in the case of the COD complex 25.4° [2] and for the title NBD complex 8.8°. Z. Kristallogr. NCS 222 (2007) 463-464 / DOI 10.1524/ncrs.2007.0195 463 © by Oldenbourg Wissenschaftsverlag, München Crystal: red block, size 0.3 × 0.4 × 0.5 mm Wavelength: Mo K radiation (0.71073 Å) : 8.54 cm−1 Diffractometer, scan mode: Stoe IPDS II, / 2 max: 53.5° N(hkl)measured, N(hkl)unique: 38897, 5344 Criterion for Iobs, N(hkl)gt: Iobs > 2 (Iobs), 5037 N(param)refined: 330 Programs: SHELXS-97 [3], SHELXL-97 [4] Table 1. Data collection and handling. H(1A) 4a 0.6424 0.5377 0.1485 0.049 H(2A) 4a 0.5630 0.6919 0.0958 0.044 H(3A) 4a 0.5189 0.6653 −0.0342 0.044 H(4A) 4a 0.3403 0.5349 −0.0407 0.052 H(5A) 4a 0.4175 0.3789 0.0104 0.058 H(6A) 4a 0.6518 0.4018 0.0541 0.057 H(7A) 4a 0.6378 0.4996 −0.0618 0.058 H(7B) 4a 0.7263 0.5627 −0.0078 0.058 H(12A) 4a 0.5142 0.6036 0.2728 0.040 H(13A) 4a 0.4842 0.7199 0.3597 0.051 H(13B) 4a 0.3297 0.7079 0.3580 0.051 H(14A) 4a 0.3791 0.8535 0.2913 0.055 H(14B) 4a 0.4841 0.7940 0.2461 0.055 H(15A) 4a 0.2086 0.7682 0.2430 0.039 H(16A) 4a 0.4651 0.5137 0.3757 0.077 H(16B) 4a 0.4192 0.4531 0.3086 0.077 H(16C) 4a 0.3156 0.5114 0.3548 0.077 H(17A) 4a 0.2785 0.8823 0.1578 0.079 H(17B) 4a 0.2181 0.7867 0.1211 0.079 H(17C) 4a 0.3714 0.8005 0.1245 0.079 H(18A) 4a 0.1139 0.4946 −0.0070 0.039 H(19A) 4a −0.1108 0.4272 0.0659 0.052 H(19B) 4a −0.0835 0.4175 −0.0162 0.052 H(20A) 4a 0.0838 0.3044 0.0020 0.063 H(20B) 4a −0.0327 0.2661 0.0500 0.063 H(21A) 4a 0.0628 0.3174 0.1509 0.041 H(22A) 4a −0.0432 0.6204 −0.0069 0.114 H(22B) 4a 0.0837 0.6543 0.0341 0.114 H(22C) 4a −0.0424 0.6215 0.0763 0.114 H(23A) 4a 0.1981 0.1896 0.1106 0.086 H(23B) 4a 0.2804 0.2674 0.1550 0.086 H(23C) 4a 0.2881 0.2685 0.0718 0.086 Table 2. Atomic coordinates and displacement parameters (in Å). Atom Site x y z Uiso
TL;DR: The readily available benzodihydropentalene 6 and dimethyl acetylene-dicarboxylate react to give norbornadiene diester 8, with a three-carbon bridge from C1 to C2 as discussed by the authors.
Abstract: The readily available benzodihydropentalene 6 and dimethyl acetylene-dicarboxylate react to give norbornadiene diester 8, with a three-carbon bridge from C1 to C2. Inrradiation of 8 gives the corresponding C1-C2 bridged quadricyclane diester 9, a new ring system. Diester 9 is quite stable, reverting to 8 with a t1/2 of 30 min at 170°C. The corresponding diacid 11, also prepared, reverts to its norbornadiene precursor at a considerably lower temperature, possibly as a consequence of acid catalysis.