Regioselective dehydroxytrifluoromethylthiolation of allylic and propargylic alcohols with AgSCF3
作者:Yin-Li Liu、Xiu-Hua Xu、Feng-Ling Qing
DOI:10.1016/j.tetlet.2019.02.045
日期:2019.4
reaction of easily available Morita–Baylis–Hillman (MBH) alcohols with AgSCF3 in the presence of n-Bu4NI and KI affords primary allylic SCF3 products in high yields and excellent regioselectivities. This regioselective dehydroxytrifluoromethylthiolation protocol could also be extended to propargylicalcohols for the preparation of the primary propargylic SCF3 products.
A novel tandem Pd-catalyzed intramolecular allylic decarboxylative coupling and “diradical conjugated 1,3-dien-5-yne cycloaromatization”: An unusual ortho -selectivity in the cycloaromatization and the mechanistic implications
hindered cyclization products (12–23) via the unusual ortho-selective cycloaromatization; while the meta-alkoxy (1i–m, 1r–t) group provided predominantly the ortho-selective 1,3-dien-5-yne cycloaromatization products, meta-Me group (1 n–q), products formed both via ortho-selective cyclization and para-selective cyclization products in comparable ratio. A novel mechanism involving diradical species
a cinchonine derived alkaloid, catalyzed asymmetric SN2′–SN2′ reaction between N-2,2,2-trifluoroethylisatin ketimines and MBH type carbonates was realized in a simple and efficient way. A series of chiral α-trifluoromethylamines were prepared with excellent yields and stereoselectivities. A subsequent and easy process of deprotection gave γ-trifluoromethyl-α-methylenelactam in a stereoselective manner
通过简单有效的方法,实现了由辛可宁衍生的生物碱β-异cupreidine催化的N -2,2,2-三氟乙基异丁酮酮与MBH型碳酸盐之间的不对称S N 2'–S N 2'反应。制备了一系列具有优异收率和立体选择性的手性α-三氟甲基胺。随后且容易的脱保护过程以立体选择性的方式得到了γ-三氟甲基-α-亚甲基内酰胺。
Radical Allylation: E-Selective Radical Conjugate Addition–Elimination Reaction from Morita–Baylis–Hillman Adducts
作者:Thierry Lequeux、Cyril Lebargy、Coralie De Schutter、Remi Legay、Emmanuel Pfund
DOI:10.1055/s-0036-1590922
日期:2018.1
Triethylborane-mediated radical allylation was performed from Morita–Baylis–Hillman alcohols with no need of protecting group. The radicalconjugated addition–elimination reaction is highly selective, and trisubstituted E-alkenes were obtained. This reaction opened a new route for the preparation of functionalized α,β-unsaturated ketones.
overcome this drawback, the effects of pyridinium-based ionic liquids mediated quinuclidine catalytic system for MBH reactions were studied. The method is simple, involving neat and open-flask conditions, and is compatible with a wide range of reagents. We offered general pyridinium-based ionic liquids-mediated quinuclidine catalysis mechanism that is responsible for the observed rate increase. The synthetic