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Organosulfide‐Catalyzed Diboration of Terminal Alkynes under Light
Author(s) -
Yoshimura Aya,
Takamachi Yuki,
Han LiBiao,
Ogawa Akiya
Publication year - 2015
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201502425
Subject(s) - borylation , sulfide , catalysis , chemistry , photochemistry , metal , electron paramagnetic resonance , terminal (telecommunication) , combinatorial chemistry , organic chemistry , aryl , alkyl , physics , nuclear magnetic resonance , telecommunications , computer science
An efficient metal‐free diboration of terminal alkynes is reported. In the presence of a catalytic amount of organosulfides under light, the addition of bis(pinacolato)diboron (B 2 pin 2 ) to terminal alkynes takes place efficiently to produce the corresponding double borylation products in good yields. Mechanistic studies indicate that this metal‐free sulfide‐catalyzed diboration of alkynes likely occurs by generation of a boryl‐centered radical with the aid of light and a sulfide, since such a radical was detected in the reaction mixture by electron spin resonance (ESR) spectroscopy. The present form of catalysis (sulfide/light) is thought to be unprecedented and provides a new means of preparation for organoboranes without heavy metal contamination in the products, which is highly desired in the preparation of drugs and electronic materials.