14159-61-6Relevant articles and documents
Photocatalyzed Site-Selective C(sp3)-H Functionalization of Alkylpyridines at Non-Benzylic Positions
Fukuyama, Takahide,Nishikawa, Tomohiro,Yamada, Keiichi,Ravelli, Davide,Fagnoni, Maurizio,Ryu, Ilhyong
, p. 6436 - 6439 (2017)
Tetrabutylammonium decatungstate (TBADT)-photocatalyzed C-H functionalization of alkylpyridines was investigated. Unlike alkylbenzene counterparts, alkylation of α-C-H bonds did not proceed for the reaction of 2- and 4-alkylpyridines and reluctantly proceeded for 3-alkylpyridines, which allow site-selective C(sp3)-H functionalization at nonbenzylic positions. The observed nonbenzylic site selectivities are rationalized by the polar inductive effects of pyridyl groups in the SH2 transition states. Consecutive γ-functionalization and α-bromofunctionalization were successfully carried out in selected cases.
Zn-Mediated Hydrodeoxygenation of Tertiary Alkyl Oxalates
Ye, Yang,Ma, Guobin,Yao, Ken,Gong, Hegui
supporting information, p. 1625 - 1628 (2021/01/18)
Herein we describe a general, mild, and scalable method for hydrodeoxygenation of readily accessible tertiary alkyl oxalates by Zn/silane under Ni-catalyzed conditions. The reduction method is suitable for an array of structural motifs derived from tertiary alcohols that bear diverse functional groups, including the synthesis of a key intermediate en route to estrone.
Straightforward synthesis of all stenusine and norstenusine stereoisomers
Mueller, Tobias,Dettner, Konrad,Seifert, Karlheinz
experimental part, p. 6032 - 6038 (2011/12/15)
All the stereoisomers of stenusine (1) and norstenusine (21) have been efficiently synthesized by the asymmetric hydrogenation of pyridines. The (2R,3S)- and (2R,3R)-isomers of 1, that are difficult to prepare, have been synthesized for the first time using a chemoenzymatic approach in eight steps with an 8 % total yield. All the target compounds were obtained in good stereochemical purity by using very simple and inexpensive reagents and auxiliaries. All the stereoisomers of the defensive alkaloids stenusine and norstenusine produced by Stenus beetles have been synthesized in a straightforward manner. The chiral (S) side chain is derived from (S)-2-methyl-1-butanol. For the difficult preparation of (R)-3-(2-methylbutyl) pyridine, a highly efficient chemoenzymatic approach was developed.