2294-75-9Relevant academic research and scientific papers
Enantioselective Alkylation of 2-Alkylpyridines Controlled by Organolithium Aggregation
Gladfelder, Joshua J.,Ghosh, Santanu,Podunavac, Ma?a,Cook, Andrew W.,Ma, Yun,Woltornist, Ryan A.,Keresztes, Ivan,Hayton, Trevor W.,Collum, David B.,Zakarian, Armen
supporting information, p. 15024 - 15028 (2019/10/22)
Direct enantioselective α-alkylation of 2-alkylpyridines provides access to chiral pyridines via an operationally simple protocol that obviates the need for prefunctionalization or preactivation of the substrate. The alkylation is accomplished using chiral lithium amides as noncovalent stereodirecting auxiliaries. Crystallographic and solution NMR studies provide insight into the structure of well-defined chiral aggregates in which a lithium amide reagent directs asymmetric alkylation.
Umpolung of Carbonyl Groups as Alkyl Organometallic Reagent Surrogates for Palladium-Catalyzed Allylic Alkylation
Zhu, Dianhu,Lv, Leiyang,Li, Chen-Chen,Ung, Sosthene,Gao, Jian,Li, Chao-Jun
supporting information, p. 16520 - 16524 (2018/11/23)
Palladium-catalyzed allylic alkylation of nonstabilized carbon nucleophiles is difficult and remains a major challenge. Reported here is a highly chemo- and regioselective direct palladium-catalyzed C-allylation of hydrazones, generated from carbonyls, as a source of umpolung unstabilized alkyl carbanions and surrogates of alkyl organometallic reagents. Contrary to classical allylation techniques, this umpolung reaction utilizes hydrazones prepared not only from aryl aldehydes but also from alkyl aldehydes and ketones as renewable feedstocks. This strategy complements the palladium-catalyzed coupling of unstabilized nucleophiles with allylic electrophiles by providing an efficient and selective catalytic alternative to the traditional use of highly reactive alkyl organometallic reagents.
Nickel-catalyzed reductive alkylation of halogenated pyridines with secondary alkyl bromides
Liu, Huiyan,Liang, Zhuye,Qian, Qun,Lin, Kunhua
supporting information, p. 2999 - 3007 (2014/10/16)
This article highlights Ni-catalyzed cross-electrophile coupling of halogenated pyridines with secondary alkyl bromides using zinc as the terminal reductant. With this protocol, we have successfully achieved different alkyl-substituted pyridines in modera
TMPZnOPiv?LiCl: A new base for the preparation of air-stable solid zinc pivalates of sensitive aromatics and heteroaromatics
Stathakis, Christos I.,Manolikakes, Sophia M.,Knochel, Paul
supporting information, p. 1302 - 1305 (2013/05/09)
A wide range of aryl and heteroaryl zinc pivalates bearing sensitive functionalities were prepared by selective metalation using TMPZnOPiv?LiCl, a new hindered zinc amide base. The new zinc reagents are easy-to-handle solids, which maintain their activity almost entirely (>95%) after 4 h of air exposure and smoothly undergo Negishi cross-couplings and reactions with various electrophiles such as Cu(I)-catalyzed acylations and allylations.
An efficient synthesis of 2-alkylpyridines using an alkylation/double decarboxylation strategy
Donald, Craig,Boyd, Scott
, p. 3853 - 3856 (2012/08/13)
We have discovered a novel route for synthesising 2-alkylpyridines by exploiting the decarboxylation of pyridyl malonate esters. Herein we report the synthesis of a number of examples and describe how the reaction was discovered.
Ring-closing metathesis reactions on azinium salts: Straightforward access to quinolizinium cations and their dihydro derivatives
Nunez, Ana,Abarca, Beatriz,Cuadro, Ana M.,Alvarez-Builla, Julio,Vaquero, Juan J.
experimental part, p. 4166 - 4176 (2009/09/08)
(Chemical Equation Presented) The ring-closing metathesis reaction of 1-butenyl-2-vinylpyridinium salts and 2-butenyl-1-vinylpyridinium salts using Grubbs second generation and Hoveyda-Grubbs catalysts proved to be an efficient approach to 3,4-dihydro- and 1,2-dihydroquinolizinium salts and the corresponding quinolizinium derivatives by an improved thermal oxidation in the presence of Pd/C without solvent. A comparative study showed that the quinolizinium system was obtained in better yields through the 3,4-dihydroquinolizinium route, thus allowing the synthesis of quinolizinium derivatives or improvements in the yields of some examples reported previously.
Synthesis and reactivity of novel ruthenium carbene catalysts. X-ray structures of [RuCl2(=CHSC6H5)(Pir 3)2] and [RuCl2(CHCH2CH2-C,N-2-C5H 4N)(Pir3)]
Van Der Schaaf, Paul A.,Kolly, Roman,Kirner, Hans-Jürg,Rime, Francois,Mühlebach, Andreas,Hafner, Andreas
, p. 65 - 74 (2007/10/03)
Two novel classes of very air-stable ruthenium carbene complexes have been developed. The arylthio substituted ruthenium carbenes containing two bulky phosphines are deep purple solids, whereas the 2-pyridylethanyl substituted ruthenium carbene complexes contain only one bulky phosphine and are light-brown colored. One member of each class has been characterized with X-ray crystallography. The metathesis activity of these complexes has been investigated in the polymerization of dicyclopentadiene. Several excellent catalysts were identified. Desired geltimes and initiation temperatures could be easily tuned by changing the substitution pattern on the pendant ligand in the 2-pyridylethanyl substituted ruthenium carbenes.
