The reactions of dioxanyl and cyclohexylradicals with 2- and 3-X-pyridines (X = CN, COMe, CO2Me) give a single substitution product deriving by addition at the 5- and 6-positions respectively; with 4-X-pyridines substitution occurs preferentially at the 3-position. If the reactions are carried out with protonated pyridines other positional isomers are obtained. From the synthetic point of view the
Transition-metal-free cross-dehydrogenative alkylation of pyridines under neutral conditions
作者:Xin Li、Hao-Yuan Wang、Zhang-Jie Shi
DOI:10.1039/c3nj00095h
日期:——
A mild and efficient method has been developed for the direct dehydrogenative alkylation of unprotonated pyridine derivatives. The avoidance of using acids and transition-metals makes this protocol “greener” and more practical for the synthesis of substituted pyridines.
TRIPODAL CYCLOHEXANE DERIVATIVES AND THEIR USE AS CARBOHYDRATE RECEPTORS
申请人:Miller Benjamin L.
公开号:US20100041568A1
公开(公告)日:2010-02-18
A tri-podal compound according to formula (I) wherein, each Z is the same and is a substituted or unsubstituted N-heteroaromatic single-, multiple-, or fused-ring; and each A is the same, and can represent a direct bond between the cyclohexane ring and Z, or a carboxamide group (—C(O)—N(H)—). Use of the compounds in combinatorial libraries, methods of making the tripodal compounds, sensor devices for detecting carbohydrate targets, and methods of using the tripodal compounds to detect carbohydrate targets in a sample are also disclosed.
Simple and readily available alkyl sulfoxides are shown to be suitable precursors to radicals. Alkyl sulfoxides, N-methoxy pyridinium salts and fluoride anions form electron donor–acceptor (EDA) complexes, which, upon visible-light irradiation, undergo a radical chain process to give various pyridine derivatives.