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Stepwise Suzuki−Miyaura Cross‐Coupling of Triborylalkenes Derived from Alkynyl−B(dan)s: Regioselective and Flexible Synthesis of Tetrasubstituted Alkenes
Author(s) -
Tani Tomohiro,
Takahashi Naomi,
Sawatsugawa Yuuki,
Osano Mana,
Tsuchimoto Teruhisa
Publication year - 2021
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.202001116
Subject(s) - chemistry , regioselectivity , borylation , alkene , aryl , yield (engineering) , combinatorial chemistry , medicinal chemistry , coupling reaction , stereochemistry , catalysis , organic chemistry , alkyl , materials science , metallurgy
Alkenes with three boryl groups of differing reactivities were synthesized and subsequently cross‐coupled regioselectively with aryl halides in a stepwise manner to afford tetrasubstituted alkenes. The key triborylalkene is derived from the platinum‐catalyzed diboration of alkynyl−B(dan)s with B 2 (pin) 2 . Due to excellent regioselectivity and reaction efficiency of each step starting with alkynyl−B(dan)s, tetrasubstituted alkenes with desired carbon frameworks at desired positions can be prepared in high yields. For example, an alkene with four distinct aryl groups, p ‐MeOC 6 H 4 , p ‐CF 3 C 6 H 4 , p ‐MeC 6 H 4 , and p ‐NCC 6 H 4 , was obtained in 71% overall yield via six steps, starting with the dehydrogenative borylation of p ‐MeC 6 H 4 C≡CH with HB(dan). Moreover, a variety of tetrasubstituted alkenes, including regio‐ and stereoisomers of the above tetraarylalkene, AIE‐active TPTPE and derivatives thereof, and ( Z )‐tamoxifen, a well‐known breast cancer drug, were accessed via the developed strategy.