- Methylenation of esters with bis(iodozincio)methane-TiCl2-TMEDA system
-
Methylenation of ester carbonyl group with bis(iodozincio)-methane was examined: a use of TiCl2 and amine as mediators facilitated the reaction to give vinyl ethers in good yields.
- Matsubara, Seijiro,Ukai, Katsumi,Mizuno, Tsuyoshi,Utimoto, Kiitiro
-
-
Read Online
- Pd-catalyzed Oxidative Cross-coupling of Alkyl Chromium(0) Fischer Carbene Complexes with Organoboronic Acids
-
Alkyl chromium(0) carbene complexes have been explored as the cross-coupling partners in the palladium-catalyzed reaction with aryl or alkenyl boronic acids. This coupling reaction displays the versatile reactivities of alkyl chromium(0) carbenes under palladium catalysis. Mechanistically, this transformation is proposed to involve deprotonation of the alkyl chromium carbene substrate to generate a vinyl chromium anion intermediate that undergoes transmetalation to organopalladium species and reductive elimination.
- Wang, Kang,Yang, Jinghui,Yao, Xingqi,Wang, Jianbo
-
supporting information
p. 3165 - 3168
(2018/10/15)
-
- Product studies and laser flash photolysis on alkyl radicals containing two different β-leaving groups are consonant with the formation of an olefin cation radical
-
1-Bromo-2-methoxy-1-phenylpropan-2-yl (3) and 2-methoxy-1-phenyl-1-diphenylphosphatopropan-2-yl (4) were generated under continual photolysis from the respective PTOC precursors in a mixture of acetonitrile and methanol. The radicals undergo heterolytic fragmentation of the substituent in the β-position to generate the olefin cation radical (5). Z-2-Methoxy-1-phenylpropene (15) is the major product formed in the presence of 1,4-cyclohexadiene, and is believed to result from hydrogen atom transfer to the oxygen of the olefin cation radical, followed by deprotonation. Laser flash photolysis experiments indicate that reaction between 5 and 1,4-cyclohexadiene occurs with a rate constant of ~6 × 105 M-1 s-1. 2,2-Dimethoxy-1-phenylpropane (18) is observed as a minor product. Laser flash photolysis experiments place an upper limit on methanol trapping of 5 at k 3 M-1 s-1 and do not provide any evidence for the formation of reactive intermediates other than 5. The use of two PTOC precursors containing different leaving groups to generate a common olefin cation radical enables one to utilize product analysis to probe for the intermediacy of other reactive intermediates. The ratio of 15:18 is dependent upon hydrogen atom donor concentration, but is independent of the PTOC precursor. These observations are consistent with the proposal that both products result from trapping of 5 that is formed via heterolysis of 3 and 4.
- Bales,Horner,Huang,Newcomb,Crich,Greenberg
-
p. 3623 - 3629
(2007/10/03)
-
- SYNTHESIS OF SULFUR-CONTAINING HETEROCYCLES BY THERMOLYSIS OF α-ALKYLTHIO-N-AZIRIDINYLIMINES
-
Thermolysis of α-alkylthio substituted N-aziridinylimines in refluxing toluene gave various structurally different sulfur-containing heterocycles in high yields.
- Kim, Sunggak,Cho, Chang Mook
-
p. 1971 - 1974
(2007/10/02)
-