Alkenylation and Arylation of Peptides via Ni-Catalyzed Reductive Coupling of α-<i>C</i>-Tosyl Peptides with Csp<sup>2</sup> Triflates/Halides
作者:Xianghua Tao、Guobin Ma、Yanhong Song、Yunrong Chen、Qun Qian、Deli Sun、Hegui Gong
DOI:10.1021/acs.orglett.1c02601
日期:2021.10.1
A Ni-catalyzed reductive cross-coupling between α-C-tosyl peptides and Csp2 triflates/halides has been developed. This protocol enables the formation of various unnatural di- and tripeptides containing vinyl and aryl side chains, and it expands the applications of Ni-catalyzed reductive cross-coupling in late-stage diversification of peptides.
已经开发了α-C-甲苯磺酰肽和 Csp 2三氟甲磺酸盐/卤化物之间的 Ni 催化还原交叉偶联。该协议能够形成各种含有乙烯基和芳基侧链的非天然二肽和三肽,并扩展了镍催化还原交叉偶联在肽后期多样化中的应用。
Radical Desulfur‐Fragmentation and Reconstruction of Enol Triflates: Facile Access to α‐Trifluoromethyl Ketones
作者:Xiaolong Su、Honggui Huang、Yaofeng Yuan、Yi Li
DOI:10.1002/anie.201608507
日期:2017.1.24
efficient oxidative radical desulfur‐fragmentation and reconstruction of enoltriflates for the synthesis of α‐CF3 ketones. Preliminary mechanistic studies disclosed that oxidative fragmentation to release a CF3 radical from the triflyl group of enoltriflate and subsequent addition of the CF3 radical to another enoltriflate form the desired α‐CF3 ketones. This method provides a new approach to α‐CF3
Preparation of α-amino acids <i>via</i> Ni-catalyzed reductive vinylation and arylation of α-pivaloyloxy glycine
作者:Xianghua Tao、Yanchi Chen、Jiandong Guo、Xiaotai Wang、Hegui Gong
DOI:10.1039/d0sc05452f
日期:——
This work emphasizes easy access to α-vinyl and aryl amino acids via Ni-catalyzed cross-electrophile coupling of bench-stable N-carbonyl-protected α-pivaloyloxy glycine with vinyl/aryl halides and triflates. The protocol permits the synthesis of α-amino acids bearing hindered branched vinyl groups, which remains a challenge using the current methods. On the basis of experimental and DFT studies, simultaneous
这项工作强调通过Ni 催化的工作台稳定的N-羰基保护的 α-新戊酰氧基甘氨酸与乙烯基/芳基卤化物和三氟甲磺酸酯的交叉亲电偶联,轻松获得 α-乙烯基和芳基氨基酸。该协议允许合成带有受阻支链乙烯基的 α-氨基酸,这仍然是使用当前方法的挑战。在实验和 DFT 研究的基础上,可能会同时向 Ni(0) 和 Ar-Ni( II )添加甘氨酸 α-碳 (Gly) 自由基,前者在氧化添加 C(sp 2 ) 时更受青睐) 生成的 Gly-Ni( I ) 中间体的亲电体得到关键的 Gly-Ni( III )-Ar 中间体。辅助螯合Ni 中心的N-羰基氧似乎对稳定 Gly-Ni( I ) 中间体至关重要。
Palladium-catalyzed coupling of vinyl triflates with organostannanes. Synthetic and mechanistic studies
作者:William J. Scott、J. K. Stille
DOI:10.1021/ja00271a037
日期:1986.5
The palladium-catalyzedcoupling reaction of vinyltriflates with acetylenic, vinyl, allyl, and alkyl tin reagents in the presence of lithium chloride or another suitable salt takes place in high yields under mild reaction conditions; however, benzyl and phenyl tin reagents give poor yield of coupled product. The utilization of a tin or silicon hydride reagent in place of the organotin partner yields
Nozaki−Hiyama−Kishi Reactions Catalytic in Chromium
作者:Alois Fürstner、Nongyuan Shi
DOI:10.1021/ja9625236
日期:1996.1.1
chromium-catalyzed additions of organic halides to aldehydes (“Nozaki−Hiyama−Kishi reactions”). The reactions are mediated by trimethylchlorosilane, and the active Cr2+ species is constantly recycled by means of nontoxic, commercial manganese powder as the stoichiometric reductant. This method nicely applies to different substituted aryl, heteroaryl, alkynyl, alkenyl, and allylhalides as well as to alkenyl triflates