Carbocyclization by Radical Closure onto O-Trityl Oximes: Dramatic Effect of Diphenyl Diselenide
摘要:
O-Trityl oximes of 5- and 6-iodoaldehydes undergo radical cyclization to produce oximes when treated in refluxing tetrahydrofuran (THF) with Bu3SnH, 1,1'-azobis(cyclohexanecarbonitrile), i-Pr2NEt, and diphenyl diselenide (PhSeSePh).
Intramolecular Trapping of Allenylzincs by Carbonyl Groups
作者:Suribabu Jammi、Julien Maury、Jean-Simon Suppo、Michèle P. Bertrand、Laurence Feray
DOI:10.1021/jo4022293
日期:2013.12.20
Allenylzinc formed via oxygen-promoted zinc/iodineexchangebetween propargyl iodides and diethylzinc can be trapped by intramolecular reaction with various electrophiles such as aldehydes, ketones, esters, carbamates, and imides. Potentially useful building blocks were obtained in high yields.
Palladium-catalyzed alkene-directed cross-coupling of aryliodide with another aryl halide through C-H arylation opens a unique avenue for unsymmetrical biaryl-derived molecules. However, homo-coupling of aryliodides often erodes the overall synthetic efficiency. Reported herein is a highly chemoselective Pd0 -catalyzed alkyne-directed cross-coupling of aryliodides with bromophenols, which was subsequently
Heck arylation of allyl alcohol catalyzed by Pd(0) nanoparticles
作者:Stanisława Tarnowicz、Waleed Alsalahi、Ewa Mieczyńska、Anna M. Trzeciak
DOI:10.1016/j.tet.2017.03.034
日期:2017.9
Pd(OAc)2 in water at 80 °C in the presence of a PVP-stabilizing polymer. Pd(0) NPs were successfully used in the Heckcoupling of allyl alcohol with iodo- and bromobenzenes. Iodobenzenes reacted under solventless conditions or in DMF solution producing 3-arylpropanals and 2-arylpropanals as the main products. The same products were obtained in the reaction of bromobenzene in TBAB as the reaction medium
Highly Stereoselective Synthesis of 2,5-Disubstituted 3-Vinylidene Tetetrahydrofurans via Prins-Type Cyclization
作者:Chul Shin、Satish N. Chavre、Ae Nim Pae、Joo Hwan Cha、Hun Yeong Koh、Moon Ho Chang、Jung Hoon Choi、Yong Seo Cho
DOI:10.1021/ol051058r
日期:2005.7.1
[reaction: see text]. A novel synthetic methodology for 2,5-disubstituted tetrahydrofurans having an allenyl group at the 3-position via Prins-type cyclization was developed. The reaction led to excellent selectivity and moderate to high yields.
Intramolecular Cycloaddition Approach to Fused Pyrazoles: Access to 4,5-Dihydro-2H-pyrazolo[4,3-c]quinolines, 2,8-Dihydroindeno[2,1-c]pyrazoles, and 4,5-Dihydro-2H-benzo[e]indazoles
作者:Chinmay Chowdhury、Moumita Jash、Bimolendu Das、Suparna Sen
DOI:10.1055/s-0036-1591737
日期:2018.4
synthesis of pyrazoles fused with 1,2,3,4-tetrahydroquinoline, 2,3-dihydro-1H-indene, or 1,2,3,4-tetrahydronaphthalene involves the formation of the tosylhydrazone from an aromatic substrate carrying aldehyde and acetylenic functionalities at appropriate positions, followed by base-promoted generation of the diazo compound and subsequent intramolecular 1,3-dipolar cycloaddition. A number of functional