79560-51-3Relevant articles and documents
Ortho-C–H addition of 2-substituted pyridines with alkenes and imines enabled by mono(phosphinoamido)-rare earth complexes
Lin, Hailong,Li, Yongrui,Wang, Jinyu,Zhang, Mei,Jiang, Tao,Li, Jing,Chen, Yanhui
, (2021/07/06)
We here reported a special catalytic performance of mono(phosphinoamido)-ligated rare earth complexes in ortho-C–H functionalization of pyridines with nonpolar alkenes and polar imines. Upon treatment with one equiv. of borate reagent B(C6F5)3 or [Ph3C][B(C6F5)4], complex NP1-Sc can act as an efficient catalyst for ortho-C–H alkylation of pyridines towards alkenes. In the presence of 1:1 mixed secondary amine of HN (SiMe3)2 and HNBn2, complex NP2-Gd can catalyze ortho-C–H addition of pyridines towards imines, effectively. A wide range of substrates were subjected to the catalysis to render the one step synthesis of a variety of ortho-alkylated and ortho-aminoalkylated pyridine derivatives in good yields and an excellent regioselectivity and chemoselectivity.
PYRIDINES. PARTIE IX - PLURIBENZYLATION DE LA S-COLLIDINE ET DE LA LUTIDINE-2,6
Compagnon, Paul-Louis,Kimny, Tan,Gasquez, Francoise
, p. 803 - 816 (2007/10/02)
A literature survey of the polymetalation of 2,6-lutidine 2 shows different results about the site(s) of deprotonation and condensation with various electrophiles.This discrepancy prompts us to examine the polylithiation (PhLi 3 equivalents, Et2O) of s-collidine 1, 2,6-lutidine 2 and more briefly of 2,4-lutidine 3.Polylithiation takes place exclusively at the methyl groups of the same position vs the ring nitrogen : 2- and/or 6-methyl of 1.The previous regioselectivity observed in the case of the monometalation in Et2O is maintained.From 1 and 2, polylithiation gives picolyl anions which lead by reaction with PhCH2Cl, simultaneously to mono-, di-symmetrical, di-non-symmetrical α-derivatives, and tri- and tetra-symmetrical α,α'-compounds; but no product is formed from a benzylic β-anion.In the same way, the deprotonation of 2-methyl-6-(2-phenylethyl) pyridine 17 leads to 2,6-bis (2-phenylethyl) pyridine 19 and 2-methyl-6-dibenzylmethyl pyridine 18, to the exclusion of the β-compound 2-methyl-6-(2,3-diphenylpropyl) pyridine 21.The latter compound is formed in low yield, besides 19 and 18, in the conditions of the Tchitchibabine reaction (NaNH2, toluene).The structure of the benzylated compounds was established mainly from the 1H-nmr data.No product was isolated which would result from the nucleophilic attack of the generated carbanions at the pyridine carbons.
