Fritsch–Buttenberg–Wiechell rearrangement of magnesium alkylidene carbenoids leading to the formation of alkynes

• Main Authors: Tsutomu Kimura, Koto Sekiguchi, Akane Ando, Aki Imafuji
• Format: Article
• Language: English
• Published: Beilstein-Institut 2021-05-01
• Series: Beilstein Journal of Organic Chemistry
• Subjects: alkyne; 1-chlorovinyl <i>p</i>-tolyl sulfoxide; dft calculation; fritsch–buttenberg–wiechell rearrangement; magnesium alkylidene carbenoid
• Online Access: https://doi.org/10.3762/bjoc.17.94
• ISSN: 1860-5397

A series of 1-heteroatom-substituted vinyl <i>p</i>-tolyl sulfoxides were prepared and treated with organometallic reagents to evaluate which combination of sulfoxides and organometallic reagents yielded alkynes the most efficiently. The use of 1-chlorovinyl <i>p</i>-tolyl sulfoxide and isopropylmagnesium chloride was optimal for this purpose. A variety of 1-chlorovinyl <i>p</i>-tolyl sulfoxides were prepared from carbonyl compounds and chloromethyl <i>p</i>-tolyl sulfoxide and were converted into alkynes via the sulfoxide/magnesium exchange reaction and subsequent Fritsch–Buttenberg–Wiechell (FBW) rearrangement of the resulting magnesium alkylidene carbenoids. The mechanism of the FBW rearrangement of magnesium alkylidene carbenoids was studied by using ¹³C-labeled sulfoxides and by using DFT calculations.