Bismuth(III) bromide in organic synthesis. A catalytic method for the allylation of tetrahydrofuranyl and tetrahydropyranyl ethers

Novel Dilute Bismide, Epitaxy, Physical Properties and Device Application

“…Due to the large amount of As Ga antisites, the GaAs reference samples reveal residual compressive strain which decreases from 128 arcsec to 20 arcsec when increasing growth temperature from 220 • C to 315 • C. After the RTA at 500 • C for 30 s, the strain in the GaAs sample grown at 220 • C decreases to 11 arcsec, i.e., almost relieved. This is due to the diffusion of As Ga antisites to As clusters [3]. For GaAsBi, the estimated Bi content is 1.46%, 1.29% and 1.30% for the samples grown at 220, 270 and 315 • C, respectively.…”

“…Surprisingly, the toxicity of Bi is even less than table salt (NaCl) [2] and it is therefore regarded as green element compared with its neighboring heavy metals like lead (Pb), antimony (Sb), arsenic (As) and mercury (Hg), etc. [3]. For this sustainability reason, Bi has recently attracted great attention to replace the toxic lead products in industry [4], and the price for Bi mine production has increased five times since 2000 [1].…”

“…Even without Bi, GaAs grown at temperatures below 300 °C contains a significant amount of native defects such as As antisites (AsGa) [138] and Ga vacancies (VGa) [139]. Upon postgrowth thermal annealing, the As antisites are converted to As clusters [3] leading to high resistivity Except for the above growth parameters, As specie was also reported to have some influence on MBE growth of GaAsBi [44,135]. The optimum growth control for Bi incorporatin in GaAs without forming Ga or Bi droplets is less strict when using As 4 other than As 2 as the As source.…”

“…Even without Bi, GaAs grown at temperatures below 300 • C contains a significant amount of native defects such as As antisites (As Ga ) [138] and Ga vacancies (V Ga ) [139]. Upon post-growth thermal annealing, the As antisites are converted to As clusters [3] leading to high resistivity [140]. Incorporating Bi into GaAs is believed to diminish the As antisties [141] and enhance PL.…”

Applications of bismuth(iii) compounds in organic synthesis

“…Although a similar methodology did not work well with THP ethers when Bi(OTf) 3 was used as the catalyst, BiBr 3 proved effective. 229 Again, the use of a relatively nontoxic catalyst, and solvent-free conditions make this methodology attractive for the synthesis of highly functionalized esters from tetrahydrofuranyl (THF) and tetrahydropyranyl THP ethers (Scheme 143). In all cases, the allylated tetrahydropyran and the corresponding acetate were obtained as by-products.…”