73922-80-2Relevant articles and documents
Rhodium-Catalyzed C?H Activation/Annulation Cascade of Aryl Oximes and Propargyl Alcohols to Isoquinoline N-Oxides
Li, Yuan,Fang, Feifei,Zhou, Jianhui,Li, Jiyuan,Wang, Run,Liu, Hong,Zhou, Yu
supporting information, p. 3305 - 3310 (2021/05/17)
A β-hydroxy elimination instead of common oxidization to carbonyl group in secondary propargyl alcohols was successfully developed to form 2-benzyl substituted isoquinoline N-oxides by a Rhodium-catalyzed C?H activation and annulation cascade, in which moderate to excellent yields (up to 92%) could be obtained under mild reaction conditions, along with good regioselectivity, broad generality and applicability. (Figure presented.).
Straightforward Stereoselective Synthesis of Seven-Membered Oxa-Bridged Rings through in Situ Generated Cycloheptenol Derivatives
Wang, Mengdan,Yin, Liqiang,Cheng, Lu,Yang, Yajie,Li, Yanzhong
, p. 12956 - 12963 (2021/09/13)
An iodine-mediated stereoselective synthesis of seven-membered oxa-bridged rings via in situ generated cycloheptenols was reported. This process was realized through the combination of C-C σ-bond cleavage and C-O bond-forming reactions in a one-pot fashion from simple and easily accessible raw materials. The formation of carbon radicals initiated by I2 was the key to the reaction.
Au(I)-catalyzed cycloaddition pathways of non-terminal propargyl substrates
Siah, Huey-San Melanie,Jónsson, Helgi Freyr,Fiksdahl, Anne
supporting information, p. 1758 - 1773 (2020/05/25)
Novel chiral menthol-based pyridyl nitrone ligands were synthesized and Au(I) coordination of the ligands gave chiral Au(I)–nitrone complexes. 1H NMR studies of the gold(I) coordination experiments with nitrone ligands afforded a convenient method for monitoring complex formation. The catalytic effect of Au(I)–nitrone complexes, shown to tune catalytic systems to produce uncommon products, was evaluated in [2 + 2 + 2] cyclotrimerization and [2 + 4] cyclodimerization reactions of non-terminal propargyl acetals. Alternative gold(I)-catalyzed [2 + 2], [2 + 4] and [3 + 4] cycloaddition reaction pathways of non-terminal propargyl acetals with imine substrates gave a diverse range of N-heterocyclic products. The present screening study demonstrates the potential and the versatility of non-terminal propargyl acetals in gold(I)-catalyzed cycloaddition reactions.
Gold-Catalyzed Hydroamination of Propargylic Alcohols: Controlling Divergent Catalytic Reaction Pathways to Access 1,3-Amino Alcohols, 3-Hydroxyketones, or 3-Aminoketones
Laserna, Victor,Porter, Michael J.,Sheppard, Tom D.
, p. 11391 - 11406 (2019/09/30)
A versatile approach to the valorization of propargylic alcohols is reported, enabling controlled access to three different products from the same starting materials. First, a general method for the hydroamination of propargylic alcohols with anilines is described using gold catalysis to give 3-hydroxyimines with complete regioselectivity. These 3-hydroxyimines can be reduced to give 1,3-amino alcohols with high syn selectivity. Alternatively, by using a catalytic quantity of aniline, 3-hydroxyketones can be obtained in high yield directly from propargylic alcohols. Further manipulation of the reaction conditions enables the selective formation of 3-aminoketones via a rearrangement/hydroamination pathway. The utility of the new chemistry was exemplified by the one-pot synthesis of a selection of N-arylpyrrolidines and N-arylpiperidines. A mechanism for the hydroamination has been proposed on the basis of experimental studies and density functional theory calculations.
Dramatic enantioselectivity reversal in the propargylation of aldehyde with alkynyllithium catalyzed by dilithium binaphtholate derivatives
Nakajima, Makoto,Watanabe, Rika,Osakama, Kazuki,Sakamoto, Midori,Takemoto, Daijiro,Kukita, Kenji
, p. 708 - 711 (2019/04/26)
A slight structural modification of a chiral catalyst caused a dramatic reversal in the enantioselectivity of an aldehyde propargylation using alkynyllithium.
Cascade Reaction of Propargyl Amines with AgSCF3, as Well as One-Pot Reaction of Propargyl Amines, AgSCF3, and Di- tert-butyl Peroxide: Access to Allenyl Thiocyanates and Allenyl Trifluoromethylthioethers
Zhen, Long,Yuan, Kun,Li, Xiu-Yan,Zhang, Chenyun,Yang, Jun,Fan, Hui,Jiang, Liqin
supporting information, p. 3109 - 3113 (2018/05/28)
An efficient cascade reaction of propargyl amines with AgSCF3 and KBr is developed, affording allenyl thiocyanates at room temperature in high yields. This transformation proceeds via the in situ formation of isothiocyanate intermediates, followed by a [3,3]-sigmatropic rearrangement. The resulting allenyl thiocyanates bearing 3-(electro-donating phenyl) substitutions without isolation can then be reacted with di-tert-butyl peroxide and AgSCF3 under reflux to generate novel allenyl trifluoromethylthioether compounds in moderate to good yields via a "one-pot" three-step process.
Efficient Synthesis of Polysubstituted Pyrroles Based on [3+2] Cycloaddition Strategy Utilizing [1,2]-Phospha-Brook Rearrangement under Br?nsted Base Catalysis
Kondoh, Azusa,Iino, Akio,Ishikawa, Sho,Aoki, Takuma,Terada, Masahiro
supporting information, p. 15246 - 15253 (2018/10/15)
An efficient method for the synthesis of polysubstituted pyrroles was established based on the [3+2] cycloaddition strategy utilizing the [1,2]-phospha-Brook rearrangement under Br?nsted base catalysis. The less-explored approach of the [3+2] cycloaddition, that is, the reaction of a C3 subunit with imines, was successfully achieved by making use of newly designed C3 subunits containing the requisite umpolung. The two-step formal [3+2] cycloaddition involves the catalytic generation of an α-oxygenated propargyl anion through the [1,2]-phospha-Brook rearrangement followed by γ-addition to the imine under Br?nsted base catalysis and the subsequent intramolecular cyclization mediated by Au catalyst or a halogenation reagent to afford polysubstituted pyrroles having a variety of substituents in a positional selective manner. The pyrroles thus synthesized were amenable to further transformations, such as palladium-catalyzed cross-coupling reactions. The operationally very simple method with readily available substrates provides new access to a diverse array of well-organized polysubstituted pyrroles.
Vanadium(V)-mediated rearrangement/halogenation cascade: Synthesis of α-haloenones from propargyl alcohols
Zhao, Meng,Mohr, Justin T.
, p. 4115 - 4124 (2017/06/29)
A method is described for the oxidative Meyer–Schuster-type rearrangement of propargylic alcohols to (Z)-α-chloro- and α-iodoenones using VOCl3 as a multifunctional reagent. The vanadium reagent is found to serve as rearrangement promoter as well as an active chlorenium ion donor. Yields are improved when VOCl3 is employed in conjunction with N-halosuccinimide reagents, giving some insights into the complex mechanism.
Metal- and Acid-Free Methyl Triflate Catalyzed Meyer-Schuster Rearrangement
Yang, Lu,Zeng, Qingle
, p. 3149 - 3156 (2017/07/12)
A novel metal- and acid-free preparation of synthetically useful α,β-unsaturated carbonyl compounds from propargyl alcohols has been realized. This Meyer-Schuster rearrangement process is effectively catalyzed by methyl triflate (20 mol%) to prepare a broad scope of conjugated E -enals and E -enones generally in good to excellent yields (up to 90%). This reaction procedure operates under mild conditions (70 °C), in air, with short reaction times (1 h). Moreover, a carbocation intermediate trapped by the solvent 2,2,2-trifluoroethanol was isolated during this transformation.
Alkynylation of aldehydes mediated by zinc and allyl bromide: a practical synthesis of propargylic alcohols
Zhou, Ji-Cai,Zhao, Lei,Li, Yuan,Fu, Ding-Qiang,Li, Zi-Cheng,Huang, Wen-Cai
, p. 4283 - 4294 (2017/06/20)
Abstract: A practical synthesis of propargylic alcohols was developed by alkynylation of aldehydes mediated by zinc and allyl bromide. Aromatic, aliphatic and vinyl aldehydes react with phenylacetylene or 1-hexyne to obtain various propargylic alcohols at room temperature in up to 98% yield. This method is characterized with inexpensive materials, wide substrate scope, and mild reaction conditions, and is also easy to scale up. In addition, this protocol is applicable to the alkynylation of α-ketone esters and epoxides to generate α-tertiary-hydroxy esters and α-alkynyl alcohols, respectively. Graphical Abstract: [Figure not available: see fulltext.].