Copper-Catalyzed Petasis-Type Reaction: A General Route to α-Substituted Amides From Imines, Acid Chlorides, and Organoboron Reagents

Abstract

A copper-catalyzed Petasis-type reaction of imines, acid chlorides, and organoboranes to form α-substituted amides is described. This reaction does not require the use of activated imines or the transfer of special units from the organoboranes and represent a useful generalization of the Petasis reaction.

Accurate Infrared (IR) Spectra for Molecules Containing the C≡N Moiety by Anharmonic Computations with the Double Hybrid B2PLYP Density Functional

“…On the other hand, the B2PLYPD3 computational model overestimates the experimental frequency by about 35 cm -1 at the harmonic level (ωB2), but inclusion of anharmonicity (νB2), decreases the discrepancy to less than 5cm -1 , a value allowing quantitative comparisons with experiment and close to that usually obtained by the most refined (and much more expensive) CCSD(T) approaches including complete basis set extrapolation. 12,19 Furthermore, anharmonic corrections evaluated at the B3LYPD3 and B2PLYPD3 levels (hereafter ∆B3 and ∆B2, respectively) are very close, thus suggesting that a hybrid method estimating the anharmonic frequency by νH = ωB2 + ∆B3 (2) could represent the best compromise between accuracy and computational efficiency avoiding at the same time the use of any empirical scaling factor.…”

“…Over the last few years, the C=N and C≡N moieties have been deeply investigated, [1][2][3][4] also in connection with their intrinsic role as intermediate in reactions involving purines and proteins, 5 not to mention the particular interest of the CN moiety for luminescent properties related to its ability of tuning the phosphorescence of some transition metal complexes. From another point of view, the simplest compound of this kind, HCN, plays a remarkable role in the interstellar space as a wide-spread small molecule 6-8 of relevance for prebiotic chemistry.…”

Copper activation of boronic acids: factors affecting reactivity

“…Furthermore, this highlights the complementarity between organocatalytic and metal‐catalysed boronic acid activations – organocatalytic methods employing diols and related compounds work best with electron‐rich boronic acids, particularly vinyl boronic acids, whereas metal‐catalysed processes make electron‐poor aryl boronic acids at least viable reaction partners, and at times they can even outperform electron‐rich analogues . To date, however, organocatalytic methods have proven more successful at enantioselective variants, though recent advances are highlighting the opportunities for metal catalysed processes …”

“…The generation of nucleophilic species via the activation of boronic acids and related compounds with copper salts is becoming a valuable strategy in synthesis . The advantages of such a system are clear: boronic acids are stable, readily available, easy to prepare, have a low toxicity and tolerate a wide range of functionalities in reaction partners, while copper salts are again very inexpensive (especially when compared with the more commonly employed noble metals) and relatively air and moisture stable.…”

Does Prop-2-ynylideneamine, HC≡CCH=NH, Exist in Space? A Theoretical and Computational Investigation

“…The chemistry of transient compounds that contain carbon-nitrogen double bonds, that is, imines [1], has recently caught the attention of many investigators [2,3,4]. This is mainly due to their instability in normal conditions, and hence act as important intermediates in many organic reactions [5,6].…”