One-pot esterification and Ritter reaction: chemo- and regioselectivity from tert-butyl methyl ether

Synthesis of Amido Esters and Amido Phosphonates through Carbonylation of Diazo Compounds Followed by Nucleophilic Addition Reaction

“…[14][15][16][17] These known methods, however, are not fully suitable to the synthesis of amido esters and amido phosphonates because of their low functional-group tolerance. [18][19][20] Nonetheless, these methods also suffer from harsh reaction conditions, low yields, and narrow substrate scopes. [18][19][20] Nonetheless, these methods also suffer from harsh reaction conditions, low yields, and narrow substrate scopes.…”

“…[11,15] Under certain reaction conditions, the Ritter reaction, the reaction of isonitriles and compounds with active methylene groups, and an amino carbonylation strategy can be employed for the synthesis of amido esters. [18][19][20] Nonetheless, these methods also suffer from harsh reaction conditions, low yields, and narrow substrate scopes. [18,20] In contrast, because of their diverse and reactive nature, ketenes are widely used as key intermediates in synthetic organic chemistry.…”

Study of the Oxidative Cleavage Proposed in the Biogenesis of Transtaganolides/Basiliolides: Pyran‐2‐one Aromaticity‐Mediated Regioselective Control and Biogenetic Implications

“…Oxidative Cleavage of Esculetin (1e): The general method described above was followed when Oxone® (2 × 1.41 g, 9.2 mmol, 8.4 equiv.) reacted with 1e (200 mg, 1.1 mmol) in 1 m phosphate aqueous buffer pH 10 (70 mL) followed by an additional 1 h. Purification of methylated reaction crude by silica column chromatography (EtOAc/hexane = 1:20 to 1:5) afforded dimethyl maleate ( 25 ) as colorless oil (7 mg, 4 % yield for two steps): 1 H NMR (400 MHz, CDCl 3 ) δ = 6.26 (s, 2H), 3.80 (s, 6H); 13 C NMR (100 MHz, CDCl 3 ) δ = 165.7, 129.7, 52.2 ( 1 H and 13 C NMR spectra are in accordance with the literature); and dimethyl 3‐methoxy‐5‐oxopimelate ( 24 ) as colorless oil (9 mg, 4 % yield for two steps): 1 H NMR (500 MHz, CDCl 3 ) δ = 4.09 (quint, J = 6.1 Hz, 1H), 3.74 (s, 3H), 3.69 (s, 3H), 3.49 (s, 2H), 3.35 (s, 3H), 2.87 (dd, J = 16.7, 7.0 Hz, 1H), 2.78 (dd, J = 16.7, 5.3 Hz, 1H), 2.59 (dd, J = 15.4, 6.1 Hz, 1H), 2.53 (dd, J = 15.4, 6.0 Hz, 1H); 13 C NMR (125 MHz, CDCl 3 ) δ = 200.7, 171.3, 167.3, 73.5, 57.4, 52.4, 51.8, 49.8, 47.1, 38.5; IR (film) ν max 2954, 2849, 1733, 1436, 1367, 1260, 1195, 1167, 1084, 996 cm – 1 ; HRMS (ESI) calcd. for C 10 H 16 O 6 Na [M + Na] + 255.0845, found 255.0855.…”

Contribution of microreactor technology and flow chemistry to the development of green and sustainable synthesis

“…The use of a flow process resulted more efficient, versatile and sustainable compared to batch. Moreover, this operationally simple procedure complements well with the already available strategies for the preparation of tert -butyl esters, avoiding the use of inflammable and explosive gaseous isobutylene [35], the use of harsh conditions [36], the use of peroxides [37], the use of toxic gas such as CO or transition metals [38–42]. The flow process, for the direct C- tert -butoxycarbonylation of organolithiums, has been optimized in a green solvent such as 2-MeTHF by a precise control of the residence time, and without using cryogenic conditions (Scheme 6).…”