Synthesis of Ketones and Esters from Heteroatom-Functionalized Alkenes by Cobalt-Mediated Hydrogen Atom Transfer
作者:Xiaoshen Ma、Seth B. Herzon
DOI:10.1021/acs.joc.6b01709
日期:2016.10.7
Cobalt bis(acetylacetonate) is shown to mediate hydrogen atom transfer to a broad range of functionalized alkenes; in situ oxidation of the resulting alkylradical intermediates, followed by hydrolysis, provides expedient access to ketones and esters. By modification of the alcohol solvent, different alkyl ester products may be obtained. The method is compatible with a number of functional groups including
A Hemilabile and Cooperative N-Donor-Functionalized 1,2,3-Triazol-5-Ylidene Ligand for Alkyne Hydrothiolation Reactions
作者:Ian Strydom、Gregorio Guisado-Barrios、Israel Fernández、David C. Liles、Eduardo Peris、Daniela I. Bezuidenhout
DOI:10.1002/chem.201604567
日期:2017.1.26
series of novel cationic and neutral Rh complexes with an N‐donor‐functionalized 1,2,3‐triazol‐5‐ylidene (TRZ) ligand (in which the pendant N donor is NHBoc, NH2, or NMe2) is described. The catalytic activity of these complexes was evaluated in the hydrothiolation of alkynes. Among the catalysts, a neutral dicarbonyl complex featuring the tethered‐NBoc amido‐TRZ ligand proved very selective for alkyne hydrothiolation
This invention relates to compounds of the formula: ##STR1## wherein R is an electron withdrawing group; R.sub.1 is H or COZ; X.sub.1 and X.sub.2 are independently H, lower alkyl, aryl, aryl lower-alkyl or polystyrene or R and X.sub.1 taken together with the carbon atoms to which they are attached form a ring containing from 4 to 15 ring carbon atoms and may contain up to 2 heteroatoms, wherein the heteroatoms are O, S, or N; and Z is an amino acid residue, a peptide residue or a leaving group. The compounds of the present invention are adaptable as blocking or protecting groups for an amine composition useful in peptide synthesis. The present invention is also directed to a method of protecting an amino group of an organic molecule during a reaction which modifies a portion of the molecule other than the protected amino group.
Synthesis of vinyl sulfides using glycerol as a recyclable solvent
作者:Eder J. Lenardão、Márcio S. Silva、Renata G. Lara、Júnior M. Marczewski、Maraisa Sachini、Raquel G. Jacob、Diego Alves、Gelson Perin
DOI:10.3998/ark.5550190.0012.222
日期:——
alkynes promoted by KF/Al2O3, usingglycerol as recyclablesolvent. This improved method furnishes selectively the corresponding anti-Markovnikov vinylsulfides in good to excellent yields starting from terminal alkynes and aliphatic or aromatic thiols. The irradiation with microwaves facilitated the procedure and accelerates the reaction. The catalytic system and the glycerol can be re-used up to four
Rhodium(<scp>i</scp>) and iridium(<scp>i</scp>) complexes with bidentate N,N and P,N ligands as catalysts for the hydrothiolation of alkynes
作者:Suzanne Burling、Leslie D. Field、Barbara A. Messerle、Khuong Q. Vuong、Peter Turner
DOI:10.1039/b303774f
日期:——
analysis. The metal complexes (9)–(12) with the mixed P,N-donor ligand, PyP are in most cases more effective in promoting the hydrothiolation of alkynes in comparison with the analogous complexes (1)–(4) with N,N-donor ligands. The iridiumcomplexes were significantly more effective than their rhodium analogues in promoting the hydrothioloation of alkynes. The cationic complexes (9) and (10) are more effective