Cyanophosphates (CPs) can be easily prepared from either ketones or aldehydes, and their reaction with NaN3–Et3N·HCl results in the formation of azidotetrazoles. Under microwave irradiation, successive fragmentation of the azidotetrazoles generates alkylidene carbenes that undergo [1,2]-rearrangement and are transformed into homologous alkynes. Treatment of ketone-derived CPs with TMSN3 and Bu2SnO
Regiodivergent Hydroaminoalkylation of Alkynes and Allenes by a Combined Rhodium and Photoredox Catalytic System
作者:Jun Zheng、Bernhard Breit
DOI:10.1002/anie.201813646
日期:2019.3.11
A rhodium/photoredox dual catalyzed regiodivergent α‐allylation of amines is described. As an atom‐economic and efficient method, alkynes and allenes are used as allylic electrophile surrogates in this novel protocol. With different reaction conditions, synthetically useful branched or linear homoallylic amines could be synthesized in good to excellent yields and regioselectivity. This straightforward
Copper-Catalyzed Synthesis of Tetrasubstituted Enynylboronates via Chemo-, Regio-, and Stereoselective Borylalkynylation
作者:Jung Tae Han、Jaesook Yun
DOI:10.1021/acs.orglett.8b00665
日期:2018.4.6
An efficient, catalytic method for accessing tetrasubstituted enynylboronates has been established via copper-catalyzed chemo-, regio-, and stereoselective borylalkynylation of internal alkynes. In this protocol, a range of symmetrical and unsymmetrical internal alkynes with aryl, heteroaryl, and alkyl substituents afforded fully substituted enynylboron compounds in good yields and with high levels
Highly Active Multidentate Ligand‐Based Alkyne Metathesis Catalysts
作者:Ya Du、Haishen Yang、Chengpu Zhu、Michael Ortiz、Kenji D. Okochi、Richard Shoemaker、Yinghua Jin、Wei Zhang
DOI:10.1002/chem.201505174
日期:2016.6
Alkynemetathesiscatalysts composed of molybdenum(VI) propylidyne and multidentate tris(2‐hydroxylbenzyl)methane ligands have been developed, which exhibit excellent stability (remains active in solution for months at room temperature), high activity, and broad functional‐group tolerance. The homodimerization and cyclooligomerization of monopropynyl or dipropynyl substrates, including challenging
Highly Active Trialkoxymolybdenum(VI) Alkylidyne Catalysts Synthesized by a Reductive Recycle Strategy
作者:Wei Zhang、Stefan Kraft、Jeffrey S. Moore
DOI:10.1021/ja0379868
日期:2004.1.1
A systematic study of alkyne metathesis catalyzed by trialkoxymolybdenum(VI) alkylidyne complexes is reported, in which substrate functional groups, alkynyl substituents, and catalyst ligands are varied. Sterically hindered trisamidomolybdenum(VI) propylidyne complex 5 was prepared conveniently through a previously communicated reductive recycle strategy. Alcoholysis of 5 with various phenols/alcohols