Rh(<scp>iii</scp>)-catalyzed diastereoselective cascade annulation of enone-tethered cyclohexadienones <i>via</i> C(sp<sup>2</sup>)–H bond activation
作者:Sandip B. Jadhav、Sundaram Maurya、N. Navaneetha、Rambabu Chegondi
DOI:10.1039/d1cc05941f
日期:——
highly diastereoselective arylative cyclization of enone-tethered cyclohexadienones via Rh(III)-catalyzed C–H activation of N-methoxybenzamides. This reaction proceeds through the formation of a five-membered rhodacycle followed by bis-Michael cascade annulation to access functionalized bicyclic scaffolds with four contiguous stereocenters with a broad substrate scope. These products have excellent functional
在此,我们报告了通过Rh( III ) 催化的N-甲氧基苯甲酰胺的C-H 活化对烯酮系环己二烯酮进行高度非对映选择性芳基化环化。该反应通过形成五元罗丹环进行,然后是双迈克尔级联环化,以访问具有广泛底物范围的具有四个连续立体中心的功能化双环支架。这些产品具有出色的功能手柄,允许进一步合成转化以增加结构复杂性。此外,还介绍了芳基化环化的机理研究和克级实验。
Enantioselective Organocatalytic Cascade Approach to Different Classes of Benzofused Acetals
A novel enantioselective organocatalytic strategy is presented for the synthesis of tetrahydrofurobenzofuran and methanobenzodioxepine naturalproductcorestructures. The strategy is based on a pair of divergent reaction pathways in which hydroxyarenes react with γ‐keto‐α,β‐unsaturated aldehydes, catalyzed by a chiral secondary amine. One reaction pathway, which leads to chiral 5,5‐fused acetals with
Synthesis of trifluoromethyl-/cyclopropyl-substituted 2-isoxazolines by DBU-promoted domino reaction
作者:Xiao-Dong Liu、Hai-Yan Ma、Chun-Hui Xing、Long Lu
DOI:10.1016/j.cclet.2017.03.031
日期:2017.8
cyclopropyl substituted 2-isoxazolines were synthesized via a DBU-promoted domino reaction of β-trifluoromethyl-/β-cyclopropyl-substituted enones with hydroxylamine. The domino reaction consists of a Michael addition and the followed cyclization. A wide range of 3-substituted 5-cyclopropyl-5- trifluoromethyl-2-isoxazolines were obtained in good to excellent yields under mild reaction conditions. The method
A Ba/Pd cooperative catalysis system was developed to enable the dehydrative cross-coupling of allylic alcohols with P-ylides to occur directly and promote a subsequent Wittigreaction in one pot. A variety of multisubstituted 1,4-dienes were isolated in good to excellent yields with broad P-ylides (stabilized by both ester and ketone carbonyl groups) and aldehyde (aliphatic and aromatic) substrates
facile and efficient one-step procedures for the regioselectivesynthesis of 7-aryl-5-methyl- and 5-aryl-7-methyl-2-amino-[1,2,4]triazolo[1,5-a]pyrimidines have been developed, via reactions of 3,5-diamino-1,2,4-triazole with variously substituted 1-aryl-1,3-butanediones and 1-aryl-2-buten-1-ones, respectively. The excellent yield and/or regioselectivity shown by the reactions decreased when ethyl 5-amino-1