4486-29-7Relevant academic research and scientific papers
Synthesis of Bridged Cyclopentane Derivatives by Catalytic Decarbonylative Cycloaddition of Cyclobutanones and Olefins
Zhou, Xuan,Ko, Haye Min,Dong, Guangbin
supporting information, p. 13867 - 13871 (2016/10/26)
Herein, we report an intramolecular rhodium-catalyzed decarbonylative coupling between cyclobutanones and alkenes that proceeds by C?C activation and provides a distinct approach to a diverse range of saturated bridged cyclopentane derivatives. In this reaction, cyclobutanones serve as cyclopropane surrogates, reacting in a formal (4+2?1) transformation. To demonstrate the efficacy of this method, it was applied in a concise synthesis of the antifungal drug Tolciclate.
Photochemical activation of distal functional groups in polyfunctional molecules. Photochemistry and photophysics of the syn-7 and anti-7-chlorobenzonorbornenes
Post,Nash,Love,Jordan,Morrison
, p. 4930 - 4935 (2007/10/02)
The spectroscopic (electronic absorption, fluorescence, and electron transmission (ET)) and photochemical properties of anti-7-chlorobenzonorbornene (BAntiCl) and syn-7-chlorobenzonorbornene (BSynCl) are reported. These are complemented by ab initio MD calculations. The BSynCl isomer, the LUMO of which contains relatively little C-Cl σ* character, is relatively unreactive upon photolysis (254 nm) in methanol (Φ(dis)(BSynCl) = 0.0014). The LUMO of BAntiCl is calculated to contain a significant amount of C-Cl σ* character, consistent with the much greater reactivity (Φ(dis)(BAntiCl) = 0.23) of this isomer. The LT spectra reveal that the π* levels of these compounds and of their exo-2- and endo-2-chlorobenzonorbornene isomers (BExoCl and BEndoCl, respectively) are appreciably stabilized relative to that of benzonorbornene (BNB). A natural bond orbital (NBO) analysis shows that much of this stabilization derives from inductive effects, with sizable through-space (TS) (0.07 and 0.10 eV) and through-bond (TB) (0.03 and 0.06 eV) coupling between the π* and C-Cl σ* orbitals for BAntiCl and BExoCl, respectively.
SYNTHESIS OF POLYCYCLIC ALKENES VIA REDUCTIVE ELIMINATION OF β-DICYANO DERIVATIVES: A FACILE PREPARATION OF ANTI-SESQUINORBORNENE AND RELATED MOLECULES
Lucchi, Ottorino De,Piccolrovazzi, Nicoletta,Modena, Giorgio
, p. 4347 - 4350 (2007/10/02)
Anti-Sesquinorbornene 1b, the hitherto unknown related unsaturated molecules 1a,c and the dienes 13 and 14 are among the endocyclic alkenes which can be prepared via reductive elimination of the respective, readily available β-dicyano derivatives.
Photolytic Cleavage of Remote Functional Groups in Polyfunctional Molecules. Photolysis of exo- and endo-Benzobicycloocten-2-yl Chloride
Morrison, Harry,Muthuramu, Kayambu,Pandey, Genesh,Severance, Daniel,Bigot, Bernard
, p. 3358 - 3363 (2007/10/02)
The aryl-induced photolytic cleavage of a remote C-Cl bond, earlier reported for the 2-position in the benzonorbornenyl series, is extended to the 2-position of the title compounds (exo-BBCl and endo-BBCl).Cleavage with 254-nm excitation is an efficient reaction (ψdis = 0.45 and 0.005, exo and endo, respectively), involving the aryl singlet excited state.Radical and carbocation derived products are observed (eq.3), with the latter including an olefin (8), a cyclopropane (9), and rearranged ethers (10 and 13) attributed to "hot" cation intermediates.The rate constants for C-Cl cleavage sre as follows: exo 1.1*109 s-1; exo 2.2.2>, 3.8*108 s-1; endo , 1.7*106 s-1; endo , 2.7*105 s-1.These rates are discussed within the context of previously proposed mechanisms.
Photolytic Cleavage of Remote Functional Groups in Polyfunctional Molecules. Photolysis of exo- and endo-2-Benzonorbornenyl Chlorides and Methanesulfonates
Morrison, Harry,Miller, Alan,Bigot, B.
, p. 2398 - 2408 (2007/10/02)
The photochemistry and photophysics of the title compounds are reported.The exo chloride exhibits a facile cleavage of the C - Cl bond upon excitation of the aryl chromophore (eq 1 - 3).The reaction has a rate > 700-fold larger than that observed with the endo isomer, derives from the singlet excited state, and leads to the formation of "hot" carbocations as well as free radicals.The exo mesylate shows similar characteristics (eq 4).A mechanism (Scheme II) is suggested which incorporates both heterolytic fission as well as sequential homolytic fission (to a polarized radical pair), followed by electron transfer to form an ion pair.The stereoelectronically controlled activation of the C - Cl and C - OMs moieties is explaned by a correlation diagram (Figure 5) which depicts the ?,?* state as correlating with the diradical product state through an avoided crossing with the C - X ?,?* state.Calculations indicate that this avoided crossing is considerably larger (and the barrier to reaction therefore considerably smaller) when the C - X unit in the 2-benzonorbornenyl series is exo.
