Development of a Catalytic Platform for Nucleophilic Substitution: Cyclopropenone-Catalyzed Chlorodehydration of Alcohols
作者:Christine M. Vanos、Tristan H. Lambert
DOI:10.1002/anie.201104638
日期:2011.12.16
Cyclopropenone makes the switch: 2,3‐Bis‐(p‐methoxyphenyl)cyclopropenone is a highly efficient catalyst for the chlorodehydration of 20 diverse alcohol substrates (see scheme; X=Cl). With oxalyl chloride as catalytic activator, this nucleophilicsubstitution proceeded through cyclopropenium‐activated intermediates and resulted in complete stereochemical inversion in substrates with chiral centers.
环丙烯酮起到了作用:2,3-双(对甲氧基苯基)环丙烯酮是一种高效的催化剂,可对20种不同的醇底物进行氯脱水(参见方案; X = Cl)。用草酰氯作为催化活化剂,这种亲核取代过程通过环丙烯活化的中间体进行,并导致具有手性中心的底物完全立体化学转化。
Cascade Ring-Opening Dual Halogenation of Cyclopropenones with Saturated Oxygen Heterocycles
saturated oxygenheterocycles, providing an efficient method for the synthesis of 3-haloacrylates. The ring-opening reaction enables the construction of two C–X (X = Cl, Br, or I) bonds and a C–O bond as well as the cleavage of two C–O bonds and a C–C bond in a single step. This protocol is highly atomeconomical, has an excellent substrate scope, and exhibits the ability for gram-scale reaction.
Rhodium(III)-Catalyzed Redox-Neutral [3+3] Annulation of N-nitrosoanilines with Cyclopropenones: A Traceless Approach to Quinolin-4(1H)-One Scaffolds
作者:Lingjun Liu、Jiyuan Li、Wenhao Dai、Feng Gao、Kaixian Chen、Yu Zhou、Hong Liu
DOI:10.3390/molecules25020268
日期:——
[3+3] cyclization of N-nitrosoanilines with cyclopropenones has been achieved. This protocol features short reaction time and atom-economical combination without extra additives, which can be further applied in the construction of privileged heterocyclic compounds in pharmaceutical chemistry.
Strain-driven palladium/N-heterocycliccarbene-catalyzed C–C bond activation of diphenylcyclopropenone (DPC) has been explored for one-step access to trisubstituted α,β-unsaturated esters and amides. The designed transformation works under mild conditions providing exclusively a single stereoisomer. Mechanisticstudies support the oxidativeaddition of the C–C bond of cyclopropenone to in-situ-generated
Synthesis and Reactions of 2,3-Diaryl- and 2,3-Dialkylcyclopropenone Imines A series of 2,3-diaryl- and 2,3-dialkylcyclopropenone iminium cations 3a-m and cyclopropenone imines 4a-i, 1, m is prepared. The ringopening reactions of imines 4a, f, i with some nucleophilic reagents (water, alcohols, pyridine) give rise to products 5-7, 10, 11, 16, 17, 20.