Applications of Diisobutylaluminium Hydride (DIBAH) and Triisobutylaluminium (TIBA) as Reducing Agents in Organic Synthesis

Reactivity of TEMPO anion as a nucleophile and its applications for selective transformations of haloalkanes or acyl halides to aldehydes

“…21 Thus, the treatment of 6f (R = PhCH=CH) with DIBAL-H (3 equivalents) at -78 to -50 °C for 75 min afforded cleanly the corresponding aldehyde 3f (91% yield) (run 3), the overreduction to carbinol was negligibly small, while ethyl trans-cinnamate, an analogue of 6f, produced the corresponding primary alcohol under the same conditions. 22 Examples of the selective reduction of 6 to aldehydes, including aldol derivative (run 5), are shown in Table 3. …”

Approaches to the tetracyclic eudistomins: the synthesis of N(10)-acetyleudistomin L

“…Diisobutylaluminum hydride (DIBAL) reduction of esters to the corresponding aldehyde is well established in the literature (24), including recent applications in which protected a-amino aldehydes are prepared from the corresponding protected a-amino esters (25). The synthesis of 5 is outlined in Scheme 4.…”

“…All the solids dissolved and the reaction mixture was refluxed for 1 h. The solvent was removed and the yellow residue chromatographed on a preparative thin-layer (neutral) alumina plate, eluting with dichloromethane-methanol(98:2), to give 30 (0.035 g, 17%) (Rf 0.85) as a white solid. Recrystallization from 95% ethanol (35% recovery) gave pure 30 as white leaflets, mp 230-234.5"C; IR (KBr) v: 355 1, 3475,3417, 3260,3081,2959, 2935, 2895, 2841, 1646, 1618, 1570, 1249, 935, 889, 844 cm-'; 'H NMR (CDC13):11 see Table 1; I3C NMR (CDC13):11 see Table 2; MS m/z (%): 469 (0.5), 467 (0.5), 454 (7), 452 (7), 384 (24), 382 (24), 380 (9), 378 (8), 338 (8) …”

Aminoborohydrides. 13. Facile reduction of N-alkyl lactams with 9-borabicyclo[3.3.1]nonane (9-BBN) and lithium aminoborohydrides (LAB) reagents

“…At 65 °C, 1-phenyl-pyrrolidin-2-one was reduced with LiH 3 BNMe 2 to give 2 (36 % by GC) and 10 (64 % by GC) in 95 % yield (Table 3, Entry 3). The reduction of 1-phenylpyrrolidin-2-one with LiH 3 BN(i-Pr) 2 at 65 °C gave a smaller, but still significant amount of amino alcohol product. Reduction of 1-phenyl-pyrrolidin-2-one with LiH 3 BN(i-Pr) 2 gave 2 (50 % by GC) and 10 (50 % by GC) in 85 % yield (Table 3, Entry 4).…”

“…1 Many reagents are available for the reduction of lactams to amines including diisobutylaluminum hydride, Encouraged by our initial results with 1-benzyl-pyrrolidin-2-one, we examined the reduction of 1-phenyl-pyrrolidin-2-one with 9-BBN. After refluxing the lactam substrate in THF for 1 h with 9-BBN, 1-phenyl-pyrrolidine (2) was obtained in essentially quantitative yield (Table 1, Entry 2). The reduction of 1-cyclohexyl-pyrrolidin-2-one containing a moderately sterically bulky N-alkyl group with 9-BBN also gave a good yield of the amine product.…”