Transition-metal complex-catalyzed reductive N-heterocyclization: synthesis of 4(3H)-quinazolinone derivatives from N-(2-nitrobenzoyl)amides

The chemistry of tryptanthrin and its derivatives

“…Intermediate 37 was treated with a catalytic amount of triruthenium dodecacarbonyl (Ru 3 (CO) 12 ) in a carbon monoxide atmosphere under vigorous conditions (140 C, 40 kg/cm -2 (~39 atm) CO pressure, 16h). 45 The yield (46%) for this transition metal catalyzed procedure was significantly lower than that reported by Kikumoto et al…”

“…[6][7][8]25,[34][35][36][37][38][39][40][41][42][43][44][45] This procedure has economic advantages, as many of the isatin and isatoic anhydride reactants are commercially available or can be easily synthesized by well established procedures.…”

A facial synthesis of quinazolino[1,4]benzodiazepine alkaloids via reductive N-heterocyclization of N-(2-nitrobenzoyl)amides: total synthesis of asperlicin C, circumdatin H, and its analogues

“…15,16 Various methods for the synthesis of alkaloids encompassing a quinazolino [1,4]benzodiazepine moiety in their skeleton have been developed and numerous research papers and several reviews have recently appeared. 1,[17][18][19][20][21][22][23][24][25][26][27] The implementations of 2-azidobenzoylamides in aza-Wittig methodology 6,[28][29][30][31][32][33] and transition metalinduced reductive N-heterocyclization [34][35][36][37][38][39] have emerged as versatile strategies for the construction of a variety of heterocyclic compounds. Although the aza-wittig and metal-induced reductive cyclization procedures afford quinazolino [1,4]benzodiazepines, they have some disadvantages such as cost and availability of the reagents such as 2-azidobenzoyl chloride and transition metals, generation of phosphine oxide by-product, harsh reaction conditions, low atom economy and synthetic practicality.…”

One-Pot Synthesis of Simple Alkaloids: 2,3-Polymethylene-4(3<i>H</i>)-quinazolinones, Luotonin A, Tryptanthrin, and Rutaecarpine

“…[4][5][6] The establishment of a simple and efficient synthetic method for these alkaloids has long been a challenging subject. [7][8][9][10][11][12][13][14][15][16][17][18][19][20] In addition, these substances are a part of the family of intriguing alkaloids that include the bronchodilator vasicinone (2a) from Adhatoda vasica, 21) antiendotoxic isaindigotone (2b) from Isatis indigotica, 22) topoisomerase Idependent cytotoxic luotonin A (3) from Peganum nigellastrum, 23) antibiotic tryptanthrin (4) from yeast (Candida lipolytica) 24,25) and later from cannon ball tree (Cououpita guianensis), 26) anti-inflammatory rutaecarpine (5) 27) from Evodia rutaecarpa, and related alkaloids (Fig. 1).…”

“…1,[30][31][32][33] Although most of these are applicable to acyclic amides, methods for cyclic amides, especially without an aryl group, are somewhat limited. [34][35][36][37] These limitations have led to the continuous development of new procedures for cyclic amides, such as cyclocondensation of isatoic anhydride with lactams, 12) metal catalyzed reductive N-heterocyclization of N-(2-nitrobenzoyl)lactams in the presence of CO,13,14) reaction of 2-aminobenzamide with succinic anhydride, 15) intramolecular aza-Wittig reaction of N-(2-azidobenzoyl)lactams, 9,16) condensation of anthranilic acid with O-alkyllactims 6,[18][19][20] or S-alkyllactims, 8) reaction of anthranilic acid with SOCl 2 followed by cyclization with lactams, 17) cyclization of iminochlorides generated from lactam and methyl anthranilate, 11) solid-phase synthesis, 7,9) and microwave assisted synthesis.10,12) Nevertheless, the biological importance of 4(3H)-quinazolinone and related compounds still spurred the development of a new and simple synthetic method for theses compounds. [38][39][40][41][42][43] As a part of our research on biologically important natural products, we herein described a simple one-pot procedure for the preparation of 1 as well as related alkaloids 3, 4 and 5 in multi-gram quantity.…”