Stereoselective Access to Highly Substituted Vinyl Ethers via trans-Difunctionalization of Alkynes with Alcohols and Iodine(III) Electrophile

Abstract

A method for the regio-and stereoselective synthesis of highly substituted vinyl ethers via trans-1,2-difunctionalization of alkynes with a cyclic λ 3-iodane electrophile (benziodoxole triflate) and alcohols is reported. The reaction tolerates a variety of internal and terminal alkynes as well as various alcohols, affording β-λ 3-iodanyl vinyl ethers in good yields with high regio-and stereoselectivities. The benziodoxole moiety of the products can be used as a versatile linchpin for the synthesis of structurally diverse vinyl ethers that are difficult to access by other means. File list (2) download file view on ChemRxiv DW_vinylether_manuscript.pdf (1.47 MiB) download file view on ChemRxiv DW_vinylether_SI.pdf (14.22 MiB)

Fluorohydration of alkynes via I(I)/I(III) catalysis

“…Through isotope-shift experiments (please see Supporting Information File 1 ), it was possible to establish that the aryl ketone of the product contains the 18 O atom (Δδ C = 4.42 Hz) [ 57 – 59 ]. Formation of the corresponding enol [ 60 ], tautomerisation and displacement liberates the α-fluoroketone and regenerates the ArI catalyst.…”

Preparation, Structure, and Reactivity of Pseudocyclic β‐Trifluorosulfonyloxy Vinylbenziodoxolone Derivatives

“…Based on the blank experiment results, and previously reported related synthesis reactions, [2j,12a,16] we proposed the reaction mechanism for preparation of pseudocyclic β‐trifluorosulfonyloxy vinylbenziodoxolone 7 and β‐azido vinylbenziodoxolone 10 (Scheme 8). Firstly, IBAs 5 react with TfOH to generated IBA‐TfOH 6 in the reaction mixture.…”

“…Several research groups have reported general synthetic procedures for the preparation of vinylbenziodoxolones by addition of various nucleophiles to the triple bond of alkynylbenziodoxolones, [2g,h,k,3] or by reactions of activated hydroxybenziodoxole (IBA) with alkynes [2j,4] or alkenylboronic acids [2a,e] . In 2015, our group reported preparation of the pseudocyclic vinylbenziodoxolone derivative 7 a by the reaction of a highly electrophilic IBA‐TfOH 6 with trimethylsilyl‐substituted acetylene (Scheme 1).…”

“…Recently, vinylbenziodoxolones 4 have attracted a significant research interest as potentially important reagents for electrophilic alkenylations [1p,2] . In particular, vinylbenziodoxolones have been used for vinylation of various substrates, such as vinylation of sulfur, [2a,b] oxygen, [2c] phosphine, [2d] or carbon atoms, [2e] and alkenylation reactions using metal reagents have been developed [2f–k] …”

Stereoselective Synthesis of Cyclobutanes by Contraction of Pyrrolidines

“…Here, PIDA serves as a decarboxylative reagent and as a source of iodonitrene, promoting electrophilic amination of the resulting imine, which gives a diazirine after oxidative cleavage of the iodine species. Inspired by these elegant synthetic methods and our long-term interest in both catalytic [3 + 2] cycloaddition reactions , and hypervalent iodine­(III) chemistry, − we were curious about the potential outcomes of the electrophilic amination of pyrrolidines using iodonitrene, which has not been documented (Figure D). Here, we report a mild and efficient method for the highly stereoselective synthesis of cyclobutanes carrying diverse functionalities with different substitution patterns from readily accessible pyrrolidines using iodonitrene chemistry.…”