80214-92-2

Upstream product

• 4227-95-6 [13C]methyl iodide 
• 603-35-0 triphenylphosphine 
• 81826-67-7 [13C]-methyltriphenylphosphonium iodide 

Downstream Products

• 327048-79-3 1-triphenylphosphoranylidene-¹³C₃-2-propanone 
• 917079-41-5 13C₂-2-methoxy-6-(2,6-divinylphenyl)naphthalene 
• 1044511-75-2 13C₂-2-(2,6-divinylphenyl)naphthalene 

Relevant academic research and scientific papers

Synergistic O3 + OH oxidation pathway to extremely low-volatility dimers revealed in β-pinene secondary organic aerosol

Dimeric compounds contribute significantly to the formation and growth of atmospheric secondary organic aerosol (SOA) derived from monoterpene oxidation. However, the mechanisms of dimer production, in particular the relevance of gas- vs. particle-phase c

Conversion of methane to ethylene using an Ir complex and phosphorus ylide as a methylene transfer reagent

Cp*(Me3P)Ir(CH3)(OTf), a complex known to reversibly activate CH4 and other hydrocarbons under mild conditions, reacts with the phosphorus ylide H2CPPh3 in THF to afford two major species [Cp*(Me

Hemisynthesis of 2,3,4-13C3-1,4-androstadien-3,17-dione: A key precursor for the synthesis of 13C3-androstanes and 13C3-estranes

In this contribution, we describe two simple and efficient routes for the preparation of keto-aldehyde 1, a key intermediate for the synthesis of 13C3-androstanes and 13C3-estranes. In the first route, the targeted aldehyde 1 was obtained in 40% overall yield from 1,4-androstadien-3,17-dione (3 mmol scale) via a two-step sequence involving a one-pot, abnormal ozonolysis/sulfur oxidation/retro-Michael/ozonolysis process. Alternatively, a second route from 4-androsten-3,17-dione, using a six-step sequence, was optimized to produce 40 mmol batches of the key intermediate 1 in 42% overall yield. At the final stage, the A-ring was reconstructed through a Wittig reaction with the 1-triphenylphosphoranylidene-13C3-2-propanone 2, followed by an intramolecular condensation assisted by thioacetic acid via a Michael addition/retro-Michael reaction sequence to provide 2,3,4-13C3-1,4-androstadien-3,17-dione.

Synthesis of 13C2-benzo[a]pyrene and its 7,8-dihydrodiol and 7,8-dione implicated as carcinogenic metabolites

Synthesis of the 13C2-labelled analogues of the carcinogenic polycyclic aromatic hydrocarbon benzo[a]pyrene and its active metabolites is described. The method entails Pd-catalyzed Suzuki-Miyaura coupling of a naphthalene boronic aci

Kinetic isotope effects in cycloreversion of rhenium (V) diolates

Cycloreversion of 4-methoxystyrene from the corresponding Tp′Re(O)(diolato) complex (Tp′ = hydrido-tris-(3,5-dimethylpyrazolyl)borate) was measured competitively for various isotopomers at 103 °C. Primary (12C/13C) and secondary (1H/2H) kinetic isotope effects were determined. The primary KIEs were k12C/k13C = 1.041 ± 0.005 at the α position and 1.013 ± 0.006 at the β position. Secondary KIEs were kH/kD = 1.076 ± 0.005 at the α position and 1.017 ± 0.005 at the β position. Computational modeling (B3LYP/LACVP*+) located a transition state for concerted cycloreversion of styrene from TpRe(O)(OCH2-CHPh) exhibiting dramatically different C-O bond lengths. A Hammett study on cycloreversions of substituted styrenes from a series of Tp′Re(O)(diolato) showed dichotomous behavior for electron donors and electron-withdrawing groups as substituents: ρ = -0.65 for electron donors, but ρ = +1.13 for electron-withdrawing groups. The data are considered in light of various mechanistic proposals. While the extrusion of 4-methoxystyrene is concluded to be a highly asynchronous concerted reaction, the Hammett study reflects a likelihood that multiple reaction mechanisms are involved.

Mechanistic aspects of the alternating copolymerization of propene with carbon monoxide catalyzed by Pd(II) complexes of unsymmetrical phosphine - Phosphite ligands

The reaction steps responsible for the highly enantioselective asymmetric copolymerization of propene with carbon monoxide catalyzed by a cationic Pd(II) complex bearing an unsymmetrical chiral bidentate phosphine- phosphite, (R,S)-BINAPHOS [(R,S)-2-(diphenylphosphino)-1,1'-binaphthalen-2'- yl 1,1'-binaphthalene-2,2'-diyl phosphite = L1], have been studied. Stepwise identification and characterization were carded out for catalyst precursors (SP-4-2)- and (SP-4-3)-Pd(CH3)Cl(L1) (1a and 1b) and (SP-4-3)- [Pd(CH3)(CH3CN)(L1)]·X1 (X1 = B{3,5-(CF3)2C6H3}4) (2), and complexes related to the reaction steps, (SP-4-3)- [Pd(COCH3)(CH3CN)(L1)]·X1 (3), (SP-4-3)- and (SP-4-4)- [Pd{CH2CH(CH3)COCH3}(L1)]·X1 (4a and 4b), (SP-4-3)- [Pd{COCH2CH(CH3)COCH3}(CH3CN)(L1)]·X1 (5), and (SP-4-3)- [Pd{CH2CH(CH3)COCH2CH(CH3)COCH3}(L1]·X1 (6). An X-ray structure of alkyl complex 4a has been obtained. Studies on [Pt(CH3)2(L1)] (8) reveal that the methyl group is more stabilized at a position trans to the phosphine than at the cis position. This is consistent with the structures of 1-6 in which all carbon substituents are trans to the phosphine moiety in their major forms. On the basis of analogous studies using platinum complexes, an isomerization from (SP-4-3)-[Pd(CH3)(CO)(L1)]·X1 (13a) to the (SP-4-4) isomer (13b) is suggested to occur for the CO-insertion process 2 → 3, which results in the activation of the methyl group for the migration to the coordinated CO. Rapid equilibrium was observed between the two isomers 4a and 4b during the CO insertion process to give 5. Theoretical studies have been carded out on the transformation of 3 to 4a and 4b. The B3LYP and MPn calculations indicated that the alkene insertion into the Pd-acyl bond trans to a phosphine is more favorable than that into the Pd-acyl bond trans to a phosphite. The MM3 calculations demonstrated that one specific transition structure is more favorable than the other possible transition structures for the transformation of (SP-4-4)-[Pd(COCH3)(propene)(L1)]·X1 (14b) to 4b. The difference originates from the steric effects of the BINAPHOS ligand, and the results account for high enantio- and regioselectivities experimentally observed. The two key steps, propene insertion into 3 and CO insertion into 4, were monitored by 1H NMR spectroscopy. The activation energies for these two steps were estimated to be 19.0-19.6 kcal/mol at -20 to 0 °C, their difference being insignificant. The living nature of the copolymerization was proved. Some related chiral ligands were examined for the copolymerization. Copolymerization of other olefins with CO was also investigated.

STERICALLY CROWDED CYCLOHEXANES - 7. SYNTHESIS, CRYSTAL STRUCTURE, CONFORMATION AND DYNAMICS OF HEXASPIRODOCOSANE AND HEXASPIROTRICOSANE

The synthesis, crystal structure, conformation and dynamics of hexaspirodocosane 6 and hexaspirotricosane 7 are described.Both compounds adopt a chair conformation in the solid state and in solution.Their