Palladium-Catalyzed Highly Regio- and Stereoselective Synthesis of 4-Alkylidene-4H-3,1-benzoxazines from N-Acyl-o-alkynylanilines
摘要:
The highly regio- and stereoselective 6-exo-dig mode cyclization of N-acyl-o-alkynylanilines producing 4-alkylidene-3,1-benzoxazines occurred unpredictably by use of a proper catalyst [Pd(OAc)(2)] and an effective additive (acetic acid) under suitable reaction conditions.
Palladium-Catalyzed Highly Regio- and Stereoselective Synthesis of 4-Alkylidene-4H-3,1-benzoxazines from N-Acyl-o-alkynylanilines
摘要:
The highly regio- and stereoselective 6-exo-dig mode cyclization of N-acyl-o-alkynylanilines producing 4-alkylidene-3,1-benzoxazines occurred unpredictably by use of a proper catalyst [Pd(OAc)(2)] and an effective additive (acetic acid) under suitable reaction conditions.
Visible-light-induced tandem cyclization of 2-alkynylanilines with disulfides: a convenient method for accessing benzothiophenes under transition-metal-free and photocatalyst-free conditions
作者:Xiaoyu Xie、Pinhua Li、Qing Shi、Lei Wang
DOI:10.1039/c7ob01747b
日期:——
An efficient route to benzothiophenes via visible-light induced cyclization of 2-alkynylanilines with disulfides under transition-metal-free and photocatalyst-free conditions was developed.
Palladium-catalyzed highly regioselective 6-exo-dig cyclization and alkenylation of ortho-ethynylanilides: the synthesis of polyene-substituted benzo[d][1,3]oxazines
作者:Zhong-Jian Cai、Chao Yang、Shun-Yi Wang、Shun-Jun Ji
DOI:10.1039/c5cc06510k
日期:——
A Pd-catalyzed highly regioselective 6-exo-dig cyclization/alkenylation reaction of ortho-ethynylanilides has been developed.
The cyclization reaction of various 2-ethynylanilines, which were easily synthesized from 2-haloanilines by the palladium-catalyzed reaction with terminal alkynes, with tetrabutylammonium fluoride (TBAF) to yield 2-substituted indoles proceeded at refluxing or room temperature in THF in excellent yields without affecting the bromo, chloro, cyano, ethoxycarbonyl, and ethynyl groups.
Efficient synthesis of o-alkynyl-N-pivaloylanilines from o-acyl-N-pivaloylanilines and lithium trimethylsilyldiazomethane
作者:Yoshiyuki Hari、Tomoki Kanie、Toyohiko Aoyama
DOI:10.1016/j.tetlet.2005.12.051
日期:2006.2
Reaction of o-acyl-N-pivaloylanilines with lithium trimethylsilyldiazomethane efficiently gave the corresponding o-alkynyl-N-pivaloylanilines via alkylidenecarbene intermediates.
A new copper-catalyzed oxidativeringclosure of ethynyl anilides with diaryliodonium salts was developed for the highly modular construction of benzoxazines bearing a fully substituted exo double bond. The oxidative transformation includes an unusual 6-exo-dig cyclization step with the formation of C–O and C–C bonds.