Rhodium-catalyzed Dehydroborylation of Styrenes with Naphthalene-1,8-diaminatoborane [(dan)BH]: New Synthesis of Masked β-Borylstyrenes as New Phenylene–Vinylene Cross-coupling Modules
作者:Noriyuki Iwadate、Michinori Suginome
DOI:10.1246/cl.2010.558
日期:2010.6.5
Styrene derivatives underwent dehydroborylation with naphthalene-1,8-diaminatoborane [(dan)BH] in the presence of a cationic rhodium complex, giving β-borylstyrene derivatives in good yields. Thus prepared β-borylstyrenes bearing a chlorine or B(pin) group on their aromatic rings were utilized for the synthesis of highly conjugated molecules through stepwise cross-coupling, taking advantage of the dan group as an effective protective group for a boronyl group.
Copper‐Photocatalyzed Hydroboration of Alkynes and Alkenes
作者:Mingbing Zhong、Yohann Gagné、Taylor O. Hope、Xavier Pannecoucke、Mathieu Frenette、Philippe Jubault、Thomas Poisson
DOI:10.1002/anie.202101874
日期:2021.6.21
photocatalytic hydroboration of alkenes and alkynes is reported. The use of newly-designed copper photocatalysts with B2Pin2 permits the formation a boryl radical, which is used for hydroboration of a large panel of alkenes and alkynes. The hydroborated products were isolated in high yields, with excellent diastereoselectivities and a high functional group tolerance under mild conditions. The hydroboration reactions
报道了烯烃和炔烃的光催化硼氢化反应。使用新设计的铜光催化剂和 B 2 Pin 2可以形成硼基自由基,该自由基可用于大量烯烃和炔烃的硼氢化反应。硼氢化产物以高产率分离,在温和条件下具有优异的非对映选择性和高官能团耐受性。硼氢化反应是在连续流动条件下开发的,以证明其合成效用。研究了反应机理,并提出了原位形成的硼酸盐和处于激发态的铜光催化剂之间的氧化反应,以形成硼基自由基。
Synthesis of Stereodefined 1,1-Diborylalkenes via Copper-Catalyzed Diboration of Terminal Alkynes
作者:Yang Gao、Zhong-Qian Wu、Keary M. Engle
DOI:10.1021/acs.orglett.0c01901
日期:2020.7.2
A copper-catalyzed method for the E-selective 1,1-diboration of terminalalkynes is described. The tandem process involves sequential dehydrogenative borylation of the alkyne substrate with HBdan (1,8-diaminonaphthalatoborane), followed by hydroboration with HBpin (pinacolborane). This method proceeds efficientlyunder mild conditions, furnishing 1,1-diborylalkenes with excellent stereoselectivity
Under zinc Lewis acid catalysis, terminal alkynes coupled dehydrogenatively with 1,8‐naphthalenediaminatoborane [HB(dan)]. It is important to note that the resulting alkynylboranes with an C(sp)B(dan) bond are isolable by column chromatography on silica gel (SiO2) and are usable as coupling partners for palladium‐ and copper‐catalyzedcross‐coupling reactions with (hetero)aryl halides.
Mixed diboration of alkenes in a metal-free context
作者:Nuria Miralles、Jessica Cid、Ana B. Cuenca、Jorge J. Carbó、Elena Fernández
DOI:10.1039/c4cc08743g
日期:——
Simultaneous addition of two different boryl moieties to alkenes with unequivocal formation of the less reactive C–B bond in the internal position, assisted by OMe−.