Directed Regioselective Carbometallation of 1,2‐Dialkyl‐Substituted Cyclopropenes
作者:Yair Cohen、Ilan Marek
DOI:10.1002/anie.202111382
日期:2021.12.6
The copper-catalyzedcarbomagnesiation reaction of cyclopropenes is a well-established method for the synthesis of stereodefined cyclopropanes. All existing reports to date proceeded towards the formation of the electronically more stable organometallic intermediate. Herein we report a regioselective addition to 1,2-dialkyl-substituted cyclopropene possessing a tethered directing group to direct the
Rhodium‐Catalyzed Remote Borylation of Alkynes and Vinylboronates
作者:Minghao Zhang、Zheming Liu、Wanxiang Zhao
DOI:10.1002/anie.202215455
日期:2023.1.26
of internal alkynes and stericallyhindered tri- and tetra-substituted vinylboronates enabled by rhodium catalysis is reported. The 1,n-diboronate products can be converted to a variety of useful building blocks, biologically active molecules, and drugs via the selective manipulation of the two boryl groups in products including the regioselective cross coupling, oxidation, and amination.
Modular synthesis of tetra-substituted furans from alkynes, Weinreb amides, and aldehydes
作者:Sajan Silwal、Ronald J. Rahaim
DOI:10.1016/j.tetlet.2015.09.021
日期:2015.10
A method for the modular one-pot synthesis of tetra-substituted furans utilizing alkynes, Weinreb amides, and non-enolizable aldehydes has been developed. Under this titanium promoted method, furans were prepared in moderate yields with high levels of regioselectivity. The system showed good chemoselectivity tolerating aromatic and aliphatic bromides, chlorides, and fluorides, heteroaromatics, alkenes, and silyl ethers. (C) 2015 Elsevier Ltd. All rights reserved.
A convenient titanium-mediated intermolecular alkyne–carbonate coupling reaction
作者:Andrzej Wolan、Frédéric Cadoret、Yvan Six
DOI:10.1016/j.tet.2009.07.015
日期:2009.9
A direct diastereoselective titanium-mediated intermolecular coupling of internal alkynes with dialkyl carbonates under Kulinkovich-type reaction conditions is presented. The influence of the structures of the coupling partners on the yields and regioselectivities of this transformation is described. (C) 2009 Elsevier Ltd. All rights reserved.