Oxidative cross-coupling of pyridine N-oxides and ethers between C(sp<sup>2</sup>)–H/C(sp<sup>3</sup>)–H bonds under transition-metal-free conditions
作者:Wei Sun、Zuguang Xie、Jie Liu、Lei Wang
DOI:10.1039/c5ob00237k
日期:——
A novel and efficient method based on the cross-coupling reactions of pyridine N-oxides with ethers between C(sp2)–H/C(sp3)–H bonds in the presence of TBHP was developed. The strategy provides an alternative approach to the pyridine moiety under transition-metal-free conditions.
Base-promoted, deborylative secondary alkylation of N-heteroaromatic N-oxides with internal gem-bis[(pinacolato)boryl]alkanes: a facile derivatization of 2,2′-bipyridyl analogues
作者:Chiwon Hwang、Woohyun Jo、Seung Hwan Cho
DOI:10.1039/c7cc03731g
日期:——
A base-promoted, secondary alkylation of N-heteroaromatic N-oxides using internal gem-bis[(pinacolato)boryl]alkanes as alkylation reagents is reported. The reaction exhibit broad scope, providing deoxygenated secondary alkylated N-heteroaromatic compounds with high efficiency. The usefulness of the developed protocol is evidenced by sequential direct alkylation of 2,2′-bipyridine-N-oxide.
Transition-Metal-Free Regioselective Alkylation of Pyridine <i>N</i>
-Oxides Using 1,1-Diborylalkanes as Alkylating Reagents
作者:Woohyun Jo、Junghoon Kim、Seoyoung Choi、Seung Hwan Cho
DOI:10.1002/anie.201603329
日期:2016.8.8
Reported herein is an unprecedented base‐promoted deborylative alkylation of pyridine N‐oxides using 1,1‐diborylalkanes as alkyl sources. The reaction proceeds efficiently for a wide range of pyridine N‐oxides and 1,1‐diborylalkanes with excellent regioselectivity. The utility of the developed method is demonstrated by the sequential C−H arylation and methylation of pyridine N‐oxides. The reaction