Methylprenyl and Prenyl Protection for Sulfonamides
摘要:
2-Methylprenyl (MePre) is an efficient protection for sulfonamides. The acidic cleavage of this group leads to volatile by-products and the product can be obtained in high purity without additional purification. MePre group is resistant to Pd/C-catalysed hydrogenolysis at 1 atm, Suzuki-Miyaura reaction, Ni(0) catalysis conditions and oxidising reagents such as NIS and DDQ. The prenyl (Pre) group can also be used to protect sulfonamides in certain cases; however, the substrate scope is limited due to the side product formation.
Metal-free electrochemical [3 + 2] heteroannulation of anilines with pyridines enabled by dual C–H radical aminations
作者:Mu-Jia Luo、Xuan-Hui Ouyang、Yan-Ping Zhu、Yang Li、Jin-Heng Li
DOI:10.1039/d1gc02922c
日期:——
electrochemical intermolecular [3 + 2] heteroannulation of anilines with electron-deficient pyridines enabled by dual C–H radicalaminations for producing functionally diverse benzo[4,5]imidazo[1,2-a]pyridines is described. The site-selectivity of aminations of aryl C(sp2)–H bonds relies on the electronic effect of two reaction partners: each contributed two reactive sites (a C(sp2)–H bond and a nitrogen
Ti(O-<i>i</i>-Pr)<sub>4</sub>/Me<sub>3</sub>SiCl/Mg-Mediated Reductive Cleavage of Sulfonamides and Sulfonates to Amines and Alcohols
作者:Noriaki Shohji、Tsuyoshi Kawaji、Sentaro Okamoto
DOI:10.1021/ol200740r
日期:2011.5.20
A low-valent titanium generated in situ from Ti(O-i-Pr)4, Me3SiCl, and Mg powder in THF reacted with aryl- and alkyl-sulfonamides of aryl and alkyl amines in a reductive N–S/S–O/S–C bond cleaving pathway to provide the corresponding amines and hydrocarbons (and thiols) derived from the sulfonyl moiety. The reagent could also cleave sulfonates to the corresponding alcohols.
One‐Pot Oxidative Heteroannulations of<i>N</i>‐Sulfonylanilines with Styrenes for the Construction of 5‐Aminocoumaran Derivatives
作者:Renhua Fan、Weixun Li、Yang Ye、Linfei Wang
DOI:10.1002/adsc.200800280
日期:2008.7.7
AbstractAn efficient one‐pot oxidative heteroannulation of N‐sulfonylaniline derivatives with styrene derivatives for the rapid construction of 5‐aminocoumaran derivatives is reported. Copper trifluoromethanesulfonate was found to be an excellent catalyst for the oxidative heteroannulation reactions with low reactive styrenes.