1375536-63-2Relevant academic research and scientific papers
Silver-Catalyzed anti-Markovnikov Hydroboration of C-C Multiple Bonds
Wang, Yan,Guan, Rui,Sivaguru, Paramasivam,Cong, Xuefeng,Bi, Xihe
supporting information, p. 4035 - 4038 (2019/06/14)
A simple silver salt (AgOAc)-catalyzed anti-Markovnikov-selective hydroboration of alkenes, 1,3-dienes, and alkynes with pinacolborane (HBpin) has been described. This strategy provides an efficient and practical method to access various alkyl-, allyl-, a
Cationic Co(I)-intermediates for hydrofunctionalization reactions: Regio- A nd enantioselective cobalt-catalyzed 1,2-hydroboration of 1,3-dienes
Duvvuri, Krishnaja,Dewese, Kendra R.,Parsutkar, Mahesh M.,Jing, Stanley M.,Mehta, Milauni M.,Gallucci, Judith C.,Rajanbabu
supporting information, p. 7365 - 7375 (2019/05/16)
Much of the recent work on catalytic hydroboration of alkenes has focused on simple alkenes and styrene derivatives with few examples of reactions of 1,3-dienes, which have been reported to undergo mostly 1,4-additions to give allylic boronates. We find that reduced cobalt catalysts generated from 1,n-bis-diphenylphosphinoalkane complexes [Ph2P-(CH2)n-PPh2]CoX2; n = 1-5) or from (2-oxazolinyl)phenyldiarylphosphine complexes [(G-PHOX)CoX2] (G = 4-substituent on oxazoline ring) effect selective 1,2-, 1,4-, or 4,3-additions of pinacolborane (HBPin) to a variety of 1,3-dienes depending on the ligands chosen. Conditions have been found to optimize the 1,2-additions. The reactive catalysts can be generated from the cobalt(II)-complexes using trimethylaluminum, methyl aluminoxane, or activated zinc in the presence of sodium tetrakis[(3,5-trifluoromethyl)phenyl]borate (NaBARF). The complex, (dppp)CoCl2, gives the best results (ratio of 1,2-to 1,4-addition >95:5) for a variety of linear terminal 1,3-dienes and 2-substituted 1,3-dienes. The [(PHOX)CoX2] (X = Cl, Br) complexes give mostly 1,4-addition with linear unsubstituted 1,3-dienes, but, surprisingly, selective 1,2-additions with 2-substituted or 2,3-disubstituted 1,3-dienes. Isolated and fully characterized (X-ray crystallography) Co(I)-complexes, (dppp)3Co2Cl2 and [(S,S)-BDPP]3Co2Cl2, do not catalyze the reaction unless activated by a Lewis acid or NaBARF, suggesting a key role for a cationic Co(I) species in the catalytic cycle. Regio- A nd enantioselective 1,2-hydroborations of 2-substituted 1,3-dienes are best accomplished using a catalyst prepared via activation of a chiral phosphinooxazoline-cobalt(II) complex with zinc and NaBARF. A number of common functional groups, among them,-OBn,-OTBS,-OTs, N-phthalimido-groups, are tolerated, and er's > 95:5 are obtained for several dienes including 1-alkenylcycloalk-1-enes. This operationally simple reaction expands the realm of asymmetric hydroboration to provide direct access to a number of nearly enantiopure homoallylic boronates, which are not readily accessible by current methods. The resulting boronates have been converted into the corresponding alcohols, potassium trifluororoborate salts, N-BOC amines, and aryl derivatives by C-BPin to C-aryl transformation.
Palladium-catalyzed oxidative allylation of bis[(pinacolato)boryl]methane: Synthesis of homoallylic boronic esters
Li, Chunsheng,Li, Meng,Li, Jianxiao,Wu, Wanqing,Jiang, Huanfeng
, p. 66 - 69 (2017/12/27)
A palladium-catalyzed oxidative allylation of bis[(pinacolato)boryl]methane to afford the corresponding homoallylic organoboronic esters with moderate to excellent yields is reported. This novel transformation provides an efficient strategy for the construction of homoallylic organoboronic esters in one step with a broad substrate scope. It is proposed that the palladium-catalyzed oxidative allylic C-H bond activation process may be involved in the catalytic cycle.
Copper-catalyzed/promoted cross-coupling of gem -diborylalkanes with nonactivated primary Alkyl halides: An alternative route to alkylboronic esters
Zhang, Zhen-Qi,Yang, Chu-Ting,Liang, Lu-Jun,Xiao, Bin,Lu, Xi,Liu, Jing-Hui,Sun, Yan-Yan,Marder, Todd B.,Fu, Yao
, p. 6342 - 6345 (2015/01/16)
The first copper-catalyzed/promoted sp3-C Suzuki-Miyaura coupling reaction of gem-diborylalkanes with nonactivated electrophilic reagents is reported. Not only 1, 1-diborylalkanes but also some other gem-diborylalkanes can be coupled with nonactivated primary alkyl halides, offering a new method for sp3C-sp3C bond formation and, simultaneously, providing a new strategy for the synthesis of alkylboronic esters.
Cross coupling between sp3-carbon and sp3-carbon using a diborylmethane derivative at room temperature
Endo, Kohei,Ohkubo, Takahiro,Ishioka, Takafumi,Shibata, Takanori
experimental part, p. 4826 - 4831 (2012/07/30)
A novel example of the Suzuki-Miyaura cross-coupling reaction between sp3-carbon and sp3-carbon is described. The reaction of a diborylmethane derivative with allyl halides or benzyl halides proceeded efficiently in the presence of appropriate Pd-catalysts at room temperature. The present approaches provide functionalized homoallylboronates and alkylboronates with excellent regio- and chemoselectivities.
