Accessing <i>N</i>-Acyl Azoles via Oxoammonium Salt-Mediated Oxidative Amidation
作者:John M. Ovian、Christopher B. Kelly、Vincent A. Pistritto、Nicholas E. Leadbeater
DOI:10.1021/acs.orglett.7b00060
日期:2017.3.17
An operationally simple, robust, metal-free approach to the synthesis of N-acyl azoles from both alcohols and aldehydes is described. Oxidative amidation is facilitated by a commercially available organic oxidant (4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate) and proceeds under very mild conditions for an array of structurally diverse substrates. Tandem reactions of these
Tuning the Basicity of a Metal-Templated Brønsted Base to Facilitate the Enantioselective Sulfa-Michael Addition of Aliphatic Thiols to α,β-Unsaturated<i>N</i>-Acylpyrazoles
The enantioselectiveaddition of aliphatic thiols to α,β-unsaturated N-acylpyrazoles catalyzed by a bis-cyclometalated iridium(III) complex with fine-tuned Bronsted basicity was investigated. Good to excellent yields (71–99 %) and enantioselectivities (86–98 % ee) were achieved at catalyst loadings of 0.2–2.5 mol-%. In this metal-templated catalyst design, the metal serves as a structural center and
(<i>R</i>)-DM-SEGPHOS–Ag(I)-Catalyzed Enantioselective Synthesis of Pyrrolidines and Pyrrolizidines via (1,3)- and Double (1,3)-Dipolar Cycloaddition Reactions
作者:Sumit K. Ray、Rayhan G. Biswas、Arun Suneja、Milon M. Sadhu、Vinod K. Singh
DOI:10.1021/acs.joc.7b03185
日期:2018.2.16
diastereo- and enantioselective route to access a wide range of highly substituted pyrrolidine and pyrrolizidine derivatives has been described via (1,3)- and double (1,3)-dipolar cycloaddition reactions catalyzed by the (R)-DM-SEGPHOS–Ag(I) complex. The reactions proceed smoothly at ambient temperature, affording a variety of pyrrolidines and pyrrolizidines in high yields (up to 93%) with up to 99:1 dr and
Besida, John; Brown, Roger F. C.; Colmanet, Silvano, Australian Journal of Chemistry, 1982, vol. 35, # 7, p. 1373 - 1383
作者:Besida, John、Brown, Roger F. C.、Colmanet, Silvano、Leach, David N.
DOI:——
日期:——
Enantioselective intermolecular free radical conjugate additions. Application of a pyrazole template
作者:Mukund P. Sibi、John J. Shay、Jianguo Ji
DOI:10.1016/s0040-4039(97)01353-1
日期:1997.8
An achiral pyrazole template has been evaluated in enantioselective conjugate radical additions. The enantioselectivity using the pyrazole template is inferior to those obtained from an oxazolidinone template. The two templates give products of opposite configuration using the same chiral Lewis acid. (C) 1997 Elsevier Science Ltd.