69322-49-2Relevant academic research and scientific papers
Diastereoselective and Enantioselective Conjunctive Cross-Coupling Enabled by Boron Ligand Design
Myhill, Jesse A.,Wilhelmsen, Christopher A.,Zhang, Liang,Morken, James P.
supporting information, p. 15181 - 15185 (2018/11/30)
Enantio- and diastereoselective conjunctive cross-coupling of β-substituted alkenylboron "ate" complexes is studied. Whereas β-substitution shifts the chemoselectivity of the catalytic reaction in favor of the Suzuki-Miyaura product, use of a boronic este
Synthesis of E-Alkyl Alkenes from Terminal Alkynes via Ni-Catalyzed Cross-Coupling of Alkyl Halides with B-Alkenyl-9-borabicyclo[3.3.1]nonanes
Di Franco, Thomas,Epenoy, Alexandre,Hu, Xile
supporting information, p. 4910 - 4913 (2015/10/12)
The first Ni-catalyzed Suzuki-Miyaura coupling of alkyl halides with alkenyl-(9-BBN) reagents is reported. Both primary and secondary alkyl halides including alkyl chlorides can be coupled. The coupling method can be combined with hydroboration of termina
Transfer of alk-1-enyl group from boron to boron: Preparation of B-[(E)-alk-1-enyl]-9-borabicyclo[3.3.1]nonane
Hoshi, Masayuki,Shirakawa, Kazuya,Arase, Akira
, p. 1225 - 1226 (2007/10/03)
Treatment of (E)-alk-1-enyldicyclohexylborane 1 with B-methoxy-9-borabicyclo[3.3.1]nonane (B-MeO-9-BBN) at 0 °C results in transfer of alk-1-enyl group from boron to boron to give B-[(E)-alk-1-enyl]-9-BBN 2 with retention of configuration.
Trans-vinylboranes from 9-borabicyclo[3.3.1]nonane through dehydroborylation
Colberg, Juan C.,Rane, Anil,Vaquer, Jaime,Soderquist, John A.
, p. 6065 - 6071 (2007/10/02)
The hydroboration of 1-alkynes (1) was reinvestigated by 11B NMR under optimized conditions (THF, 18 h, 0°C) and found to provide trans-vinyl-9-BBN adducts (2) together with variable amounts of 1,1-diborylalkanes (3) depending both upon the excess of 1 employed and the nature of alkyne substitution. By contrast, the formation of 3 with 2 equiv of 9-BBN-H is quantitative. A new completely stereoselective route to 2 from 3 was discovered with its reaction with ArCHO in an electrocyclic process (p = 0.42). While analogous to the Midland reduction, the term dehydroborylation is introduced to emphasize the olefination aspect of the reaction. Compound 3a (R = Me) is smoothly dehydroborylated at 25°C with PhCHO following second-order kinetics. Competitive rate studies reveal its reaction to be slower than that of Alpineborane (7) (k7/k3a = 4.5) but faster than that of B-siamyl-9-BBN (6) (k6/k3a = 0.34). The value of the dehydroborylation approach to 2 and the advantages of using 9-BBN derivatives in vinylborane reactions are demonstrated with numerous examples. Thus, 1,8-nonadiyne is converted, through a bis(vinylborane) (11), to pure trans,trans-1,9-dideuterio-1,8-nonadiene (12). This transformation has not been previously possible for 9-BBN-H because of competitive dihydroboration. The dihydroboration of 1-(triethylsilyl)-1-propyne, after thermal isomerization and deuterolysis, affords trans-(3-deuterioallyl)silane (16), a most remarkable overall conversion. The insertion of aromatic aldehydes into 2 was further demonstrated to provide a convenient entry to trans-allylic alcohols. The selective oxidation of 2 with TMANO produces trans-alkenyl-9-oxa-10-borabicyclo[3.3.2]decanes, 18, which resist further reaction with ArCHO, oxidation in the atmosphere, and protonolysis. A 1→ 3 → 2 → 20 sequence was employed without the isolation of 2 in a one-pot Suzuki coupling with ArBr to provide trans-stilbenes (20, Ar = p-C6H4X, X = OMe (80%), NMe2 (60%)).
