60815-16-9Relevant articles and documents
Organocatalytic enantio- and diastereoselective synthesis of 1,2-dihydronaphthalenes from isobenzopyrylium ions
Qian, Hui,Zhao, Wanxiang,Wang, Zhaobin,Sun, Jianwei
, p. 560 - 563 (2015)
A highly efficient asymmetric synthesis of dihydronaphthalenes is disclosed. The process represents a new addition to the limited asymmetric reactions of isobenzopyryliums, a family of versatile 10π-electron aromatic species. Excellent asymmetric induction is achieved for the first time without an anchoring group in the 4-position or a metal catalyst, both of which were required previously in these reactions. The success is attributed to the unusual chiral counteranion (meanwhile also the nucleophile) generated in situ from the chiral phosphate and the boronic acid as well as the leaving group. Preliminary control experiments provided important insight into the reaction mechanism.
Solvent-regulated coupling of 2-alkynylbenzaldehydes with cyclic amines: Selective synthesis of fused N-heterocycles and functionalized naphthalene derivatives
He, Yan,Fan, Xuesen,Zheng, Zhi,Liu, Qimeng,Zhang, Xinying
supporting information, p. 9053 - 9058 (2020/12/02)
An efficient synthesis of 1,2,3,4-tetrahydrobenzo[g]-quinoline derivatives through PdCl2-catalyzed, TBHP-promoted, and toluene-mediated dehydrogenation/[4+2] cycloaddition of saturated cyclic amines with 2-alkynylbenzaldehydes was developed. On the contrary, when the reaction medium was changed from toluene to DMSO/H2O, another class of important compounds, naphthyl chain amines, formed via a dehydrogenation?intermolecular condensation? C?N bond cleavage?intramolecular condensation pathway, was obtained with good selectivity.
Gold(i) or gold(iii) as real intermediate species in gold-catalyzed cycloaddition reactions of enynal/enynone?
Shi, Min,Wang, Gendi,Wang, Jiwei,Wei, Yin,Xu, Sheng,Yang, Xueyan,Zhan, Licheng,Zhang, Caiyun,Zhang, Jun
, p. 6682 - 6690 (2020/08/12)
Metal-bound isobenzopyrylium species are proposed as reactive intermediates in transition-metal-catalyzed [3 + 2] or [4 + 2] cyclizations of o-alkynylbenzaldehydes (enynals) or o-alkynylarylketones (enynones). Because of their high reactivity, isolation and structural characterization of such intermediates have remained elusive. Herein, we report the isolation of such gold(I)- and gold(III)-bound isobenzopyrylium intermediates, and two of them have been characterized by X-ray diffraction analysis. When reacting with reaction partners, such as styrene and phenyl acetylene, the Au(I) intermediate exhibited a reaction rate much faster than that of the Au(III) species. A degradation pathway of active Au(III)-carbene intermediate was observed, leading to release of Au(I) species and consequent formation of a dichloride compound. In other related catalytic reactions, the Au(I) intermediate could react well with a range of cyclization partners, whereas the Au(III) intermediate did not work. The above observations indicate that Au(I) species is probably the real catalyst in such gold-catalyzed transformations of o-alkynylbenzaldehydes and o-alkynylarylketones.
Copper-Catalyzed [4+2]-Cycloadditions of Isoxazoles with 2-Alkynylbenzaldehydes To Access Distinct α-Carbonylnaphthalene Derivatives: C(3,4)-versus C(4,5)-Regioselectivity at Isoxazoles
Giri, Sovan Sundar,Liu, Rai-Shung
, p. 7328 - 7334 (2019/08/26)
Cu(II)-catalyzed [4+2]-cycloadditions occur between Cu-benzopyryliums and substituted isoxazoles with the regioselectivity on the C(3,4)-carbons of isoxazoles. We postulate that a prior coordination of isoxazoles with Cu(OAc)2 increases the ?-bond character of the C(3,4) carbons to become an effective 2?-donor. In this reaction sequence, 3,5-disubstituted isoxazoles yield α,?-dicarbonylnaphthalenes whereas, 5-substituted isoxazoles deliver α,?-dicarbonyl-β-aminonaphthalenes. For unsubstituted isoxazole, its cycloaddition chemoselectivity is switched to the C(4,5)-addition regioselectivity to yield α-carbonyl-?-cyanonaphthalene derivatives.
Access to densely functionalized naphthalenes by organobase catalyzed domino reaction of 2-(2-formylaryl)acetophenones with nitroolefins
Dagar, Anuradha,Biswas, Soumen,Mobin, Shaikh M.,Samanta, Sampak
supporting information, p. 3326 - 3329 (2016/07/11)
A series of new functionalized naphthalene derivatives having carbonyl and NO2groups at C-1 and C-3 positions respectively have been prepared in good yields (63–75%) through a one-pot domino reaction of several 2-(2-formylaryl)acetophenone derivatives with a variety of aryl/heteroaryl-substituted 2-nitroolefins in EtOH as a green solvent at 75?°C under air using a catalytic amount of DABCO (30?mol?%) as an inexpensive organocatalyst. This pot-economic process is friendly enough to retain several sensitive functionalities and displays a wide range of substrate scope. Furthermore, the high yielding synthesis of biologically attractive N-(3-naphthyl-substituted)pyrrole frameworks was established through our synthetic procedure.
An efficient route to polysubstituted tetrahydronaphthols: Silver-catalyzed [4+2] cyclization of 2-alkylbenzaldehydes and alkenes
Zhu, Shifa,Liang, Renxiao,Jiang, Huanfeng,Wu, Wanqing
supporting information, p. 10861 - 10865 (2013/01/15)
Silver bullet: A methodology for stereoselective synthesis of polysubstituted tetrahydronaphthols catalyzed by [Ag+]/NPO has been developed. The reactions proceeded through an unprecedented [4+2] cyclization of 2-(2-formylphenyl)ethanone and an alkene, in both inter- and intramolecular fashion. NPO=pyridine N-oxide. Copyright
Ozonolyses of 1,2-Diphenyl- and 2-Phenylindene
Sugimoto, Toshiya,Teshima, Koichi,Nakamura, Norinaga,Nojima, Masatomo,Kusabayashi, Shigekazu,McCullough, Kevin J.
, p. 135 - 141 (2007/10/02)
Ozonolyses of 1,2-diphenylindene (7), 2-phenylindene (18), and the structurally related acyclic keto olefins 13, 14, 26, and 32 were conducted in MeOH/CH2Cl2 at -70 and 0 deg C.The structure of the indenes, 7 and 18, and the rection temperature, were foun
THERMOLYTIC RING OPENING OF ACYLOXYBENZOCYCLOBUTENES: AN EFFICIENT ROUTE TO 3-SUBSTITUTED ISOQUINOLINES
Schiess, Peter,Huys-Francotte, Martine,Vogel, Caspar
, p. 3959 - 3962 (2007/10/02)
Upon flash vacuum pyrolysis acyloxybenzocyclobutenes 4 rearrange through an intramolecular 1,5-acyl shift to 2-formylbenzyl ketones 6 which can be converted to 3-substituted isoquinolines 7.
