A Mild and Regioselective Ring-Opening of Aziridines with Acid Anhydride Using TBD or PS-TBD as a Catalyst

Abstract

Abstract:The ring-opening of N-tosylaziridines with various acid anhydrides catalyzed by 5 mol % of 1,5,7-triazabicyclo[4,4,0]dec-5-ene (TBD) afforded the corresponding β-amino esters in excellent yields under mild reaction conditions. Polymer-supported catalyst, PS-TBD also acts as a good catalyst for this reaction. PS-TBD was easily recovered and reused with minimal loss of activity.

TBD- or PS-TBD-Catalyzed One-Pot Synthesis of Cyanohydrin Carbonates and Cyanohydrin Acetates from Carbonyl Compounds

“…Polymer-supported catalysts have attracted significant attention in recent decades because of their inherent advantages in synthetic chemistry, e.g., the simplification of reaction procedures including the easy recovery of the catalyst using filtration, application to automated systems, and recycling of the catalyst [68,69,70,71,72,73]. Thus, we examined the cyanomethoxycarbonylation reaction of p -anisaldehydes in the presence of 10 mol % of PS-TBD [63,74,75,76,77,78,79]. The reaction proceeded smoothly and the desired product was obtained in 95% yield after 3 h at room temperature.…”

“…Although TBD usually behaves as a base, it also contains an acidic N–H group; therefore, TBD may act as a bifunctional acid-base catalyst [58,59,60]. Recently, we have reported the trifluoromethylation of aldehydes [61] and the ring-opening reactions of aziridines [62,63] catalyzed using TBD as an organocatalyst. Here, we report that TBD acts as an effective organobase catalyst for the cyanation of carbonyl compounds using methyl cyanoformate or acetyl cyanide as cyanide source.…”

Unique Superbase TBD (1,5,7-Triazabicyclo[4.4.0]dec-5-ene): From Catalytic Activity and One-Pot Synthesis to Broader Application in Industrial Chemistry

“…63 Miscellaneous Reactions. There are numerous other examples for the successful use of TBD in miscellaneous reactions, 64−69 e.g., Wittig and Horner-Wadsworth-Emmons reactions, 64 synthesis of cyanohydrin carbonates and acetates, 65 trifluoromethylation of carbonyl compounds, 66 ring opening reactions of aziridines, 67 and α-hydroxylation of ketones by oxygen. 68 Quite unexpectedly, however, TBD catalyzes also enantioselective reactions, such as the 1,3isomerization of optically active allyl alcohols, ethers, and chlorides (Scheme 11).…”

Ring Opening of Aziridines by Pendant Silanols Allows for Preparations of (±)-Clavaminol H, (±)-Des-Acetyl-Clavaminol H, (±)-Dihydrosphingosine, and (±)-N-Hexanoyldihydrosphingosine

“…Amino alcohols are important constituents of biologically active molecules − and have inspired the invention of many elegant techniques for their construction (Scheme ). ,, Pioneering efforts on syntheses of vicinal amino alcohols have focused on transition metal catalyzed processes to install both N- and O -moieties in a single transformation. − A complementary approach is the ring opening of epoxides with N -nucleophiles and of aziridines with O -nucleophiles. , This untethered approach − is convenient from the perspective of step counts, but challenges with regiocontrol often result in intractable product mixtures. Temporary tethering using Lewis acid templates affords excellent regiocontrol with epoxides, − but only one such report exists with aziridines .…”