Chemodivergent Synthesis of Oxazoles and Oxime Ethers Initiated by Selective C–N/C–O Formation of Oximes and Diazo Esters
作者:Zhenjie Qi、Shaozhong Wang
DOI:10.1021/acs.orglett.1c03252
日期:2021.11.5
Chemodivergent reactions of oximes and diazo esters involving Rh-catalyzed [3+2] annulation and photodriven O–H insertion have been developed to generate oxazoles and oxime ethers. A range of aldehyde and ketone oximes reacted with α-diazocarbonyl compounds in a controllable manner in which functional groups, including ketone, ester, amide, ether, thiol ether, silane, alkene, allene, and alkyne groups
Alkyl Halide-Free Heteroatom Alkylation and Epoxidation Facilitated by a Recyclable Polymer-Supported Oxidant for the In-Flow Preparation of Diazo Compounds
作者:Simon M. Nicolle、Christopher J. Hayes、Christopher J. Moody
DOI:10.1002/chem.201500118
日期:2015.3.16
simple ketones via diazocompounds, including diazo‐amides and ‐phosphonates, using a recyclable reagent in‐flow, are transient but versatile electrophiles for heteroatomalkylation reactions and for epoxide formation. The method produces no organic waste, with the only by‐products being water, KI and nitrogen, without the attendant hazards of isolation of intermediate diazocompounds.
Stereoselective Synthesis of Difluorinated 1,3-Dienes via Palladium-Catalyzed C–F Bond Activation of Tetrasubstituted <i>gem</i>-Difluoroalkenes
作者:Yanhui Wang、Qiao Ma、Gavin Chit Tsui
DOI:10.1021/acs.orglett.1c01768
日期:2021.7.2
Pd(0)-catalyzed synthesis of difluorinated 1,3-dienes is described. Symmetrical 1,3-dienes containing a vicinal difluoro moiety can be obtained as single diastereomers from tetrasubstituted gem-difluoroalkenes. The reaction presumably proceeds through a stereoselective twofold Pd-catalyzed Miyaura borylation/Suzuki–Miyaura cross-coupling of the C–F bond. Moreover, modular synthesis of unsymmetrical
Stereoselective Synthesis of Highly Substituted Tetrahydrofurans through Diverted Carbene OH Insertion Reaction
作者:Simon M. Nicolle、William Lewis、Christopher J. Hayes、Christopher J. Moody
DOI:10.1002/anie.201502484
日期:2015.7.13
Copper‐ or rhodium‐catalyzed reactions of diazocarbonyl compounds with β‐hydroxyketones give highlysubstitutedtetrahydrofurans with excellent diastereoselectivity. Under mild conditions, the single‐step process starts as a carbene OH insertion reaction, but is diverted by an intramolecular aldol reaction.
A tris(pentafluorophenyl)borane-catalyzed oxidation reaction of α-diazoesters (α-diazo amides) with dimethyl sulfoxide has been developed. The reaction proceeds under metal free conditions to afford a series α-ketoesters and α-ketoamides. The synthetic utility of this protocol is demonstrated through synthetic transformations and scaled-up synthesis.