Alkynylation of Aryl Bromides with Propargylamines Catalyzed by a Palladium-Tetraphosphine Complex
作者:Henri Doucet、Maurice Santelli、Mhamed Lemhadri
DOI:10.1055/s-2005-865284
日期:——
combination with [Pd(C 3H5 )Cl] 2 affords a very efficient catalyst for the alkynylation of aryl bromides with propargylamines. Higher reactions rates were observed with N,N-dialkylpropargylamines than with N-methylpropargylamine or propargylamine. A wide variety of substituents such as alkyl, phenyl, methoxy, dimethylamino, fluoro, trifluoromethyl, acetyl, benzoyl, formyl, carboxylate, nitro, or nitrile
四膦全顺-1,2,3,4-四(二苯基膦基甲基)环戊烷与[Pd(C 3 H 5 )Cl] 2 组合为芳基溴化物与炔丙基胺的炔基化提供了非常有效的催化剂。N,N-二烷基炔丙基胺比N-甲基炔丙基胺或炔丙基胺观察到更高的反应速率。芳基溴化物上的多种取代基如烷基、苯基、甲氧基、二甲氨基、氟、三氟甲基、乙酰基、苯甲酰基、甲酰基、羧酸酯、硝基或腈是可以接受的。使用这些芳基溴化物中的大多数都可以获得高周转数。空间上非常拥挤的芳基溴化物如 9-溴蒽或 2,4,6-三异丙基溴苯的偶联反应也以良好的收率进行。
One‐Pot Copper‐Catalyzed Cascade Bicyclization Strategy for Synthesis of 2‐(1
<i>H</i>
‐Indol‐1‐yl)‐4,5‐dihydrothiazoles and 2‐(1
<i>H</i>
‐Indol‐1‐yl)thiazol‐5‐yl Aryl Ketones with Molecular Oxygen as an Oxygen Source
作者:Jialin Xie、Zhonglin Guo、Yuanqiong Huang、Yi Qu、Hongjian Song、Haibin Song、Yuxiu Liu、Qingmin Wang
DOI:10.1002/adsc.201801193
日期:2019.2
atom‐economical method for synthesizing N‐heterocyclic indolesfrom readily available o‐alkynylphenyl isothiocyanates and propargylamine derivatives is reported. This method involves a copper‐catalyzed cascade bicyclization process consisting of an intramolecular 5‐exo‐dig hydrothiolation reaction and an intramolecular hydroamination reaction and, depending on whether or not molecular oxygen is present
Synthesis of thiazolo[2,3-<i>b</i>]quinazoline derivatives <i>via</i> base-promoted cascade bicyclization of <i>o</i>-alkenylphenyl isothiocyanates with propargylamines
A highly efficient cascade bicyclization reaction of o-alkenylphenyl isothiocyanates with propargylamines has been developed, which affords a series of thiazolo[2,3-b]quinazolines in good to excellent yields by using K2CO3 as a base in MeCN at 80 °C. This method is transition-metal-free and operationally simple with broad functional group tolerance. Mechanistically, 6-exo-trig hydroamination followed
Despite the very low acidity of the inert α C−H bonds (pKa≈42.6), directasymmetric α-C(sp3)−H addition of N-unprotected propargylic amines to trifluoromethyl ketones has been achieved by using a chiral pyridoxal as the carbonyl catalyst, producing a broad variety of chiral alkynyl β-aminoalcohols in high yields with excellent stereoselectivities (up to 84 % yield, >20 : 1 dr, 99 % ee).
尽管惰性 α C−H 键的酸度非常低 (p K a ≈ 42.6),但通过使用手性吡哆醛,已经实现了 N-未保护的炔丙胺与三氟甲基酮的直接不对称 α-C( sp 3 )−H 加成作为羰基催化剂,以高产率和出色的立体选择性(高达 84% 产率,>20:1 dr,99% ee)生产多种手性炔基 β-氨基醇。
Convenient, DBU-promoted anti-Markovnikov hydration of 2-methyl-1-(3-arylprop-2-yn-1-yl)-1H-imidazoles in wet NMP
base-promoted, allene-mediated cyclization of the alkynemoiety onto the nearby aromatic ring, substantial amount of the ketone resulting from hydration of the alkyne with adventitious water was discovered. The formation of the ketone of the anti-Markovnikov alkyne hydration was developed into a preparative method. This method, alternative to the common acid-and metal-catalyzed approaches, may be of particular