In 2022,Johnson, John Douglas; Teeples, Charles Reece; Akkawi, Nicholas Rajai; Wilkerson-Hill, Sidney M. published an article in Journal of the American Chemical Society. The title of the article was 《Efficient Synthesis of Orphaned Cyclopropanes Using Sulfones as Carbene Equivalents》.Formula: C4H7Br The author mentioned the following in the article:
Herein, a mechanistically distinct platform to transfer 1,1-dialkylcarbene units to olefins using carbometalation reactions of dialkyl sulfonyl anions was introduced. In presence of NaNH2 or n-BuLi in ethereal solvents, dialkyl sulfones reacted with styrenes and arylbutadienes between 23 and 70°C to produce corresponding 1,1-dialkylcyclopropanes, e.g., I [R1 = Me, Et, n-Bu, etc.; R2 = H, i-Bu, n-pentadecyl, etc.; R1R2 = (CH2)4, (CH2)5, (CH2)6]. Forty examples of this reactivity including 16 different styrenes (up to 89% isolated yield), 9 arylbutadienes (51-88% yield), and 13 different sulfones (46-80% yield) was reported. In addition, an example of a sequential cyclopropanation reaction using this method was reported. Preliminary mechanistic studies suggested a stepwise anionic process that was initiated by direct addition of sulfonyl anions to a carbon-carbon double bond. In the experiment, the researchers used (Bromomethyl)cyclopropane(cas: 7051-34-5Formula: C4H7Br)
(Bromomethyl)cyclopropane(cas: 7051-34-5) is used as a synthetic building block for the introduction of the cyclopropylmethyl group. It was also used in the synthesis of 1,4-dienes via iron-catalyzed cross-coupling with alkenyl Grignard reagents.Formula: C4H7Br
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary