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The synthesis of N-heterocycles has received extensive attention from scientists considering their important role in organic synthesis, pharmaceuticals, and materials chemistry. α-Amino acids (α-AAs), both natural and non-natural, are structurally diverse, containing basic amino groups, acidic carboxyl groups, and various side-chain R groups in a single molecule. Given their structural properties and wide range of sources, they have undoubtedly become suitable synthetic building blocks for organic synthesis. However, conventional transformations of amino acids (AAs) focus on the amino and carboxyl groups independently. Conversions for these two prominent functional groups generally do not affect both their alpha positions and their branched chains. Over the past decade, with the application of iodine (I2) in the field of heterocyclic synthesis, the use of α-AAs for diverse construction of complex N-heterocyclic structures has gained increasing attention. This synthetic strategy relies on the I2-mediated Strecker degradation, which introduces α-AAs as electrophilic carbon species into the domino reaction sequence via decarboxylation and deamination processes. In this review, we have summarized recent advances in this emerging area. [ABSTRACT FROM AUTHOR]

Natural product total synthesis has trailblazed in the era of multistep synthesis. The strategic application of existing synthetic methodologies and the stepwise construction that revolves around newly developed, tailored key steps, are two basic tactics in the principle of classic retrosynthetic analysis. However, a new synthetic model, termed self-organized total synthesis, has emerged in recent years, enabling the rapid creation of specific natural products by a one-pot reaction. Distinct from conventional analysis associated with certain bond disconnections, the design of self-organized total synthesis focuses on seeking a series of self-organized reaction sequences which can be integrated compatibly under a uniform condition, therefore allowing the entire sequence to proceed in one pot, and most importantly, starting from commercially available feedstocks or biomass materials. Whilst dauntingly challenging, this synthetic strategy is more consistent with the biogenetic pathway of natural products compared with conventional counterparts, and will hopefully provide the shortest synthesis for such natural products. Through this rational analysis, one-pot total synthesis is no longer in the way of serendipity but can be precisely designed and manipulated. In this review, we account for the definition, delimitation, and categorization of self-organized total synthesis and then elucidate a comprehensive understanding of this synthetic strategy based on our intensive explorations. We also highlight the contributions of other research groups in this growing field and anticipate that it will give rise to advancing new methodologies, as well as new concepts within organic synthesis. [ABSTRACT FROM AUTHOR]

An oxidant-controlled divergent synthesis of a pyrrolidone fused pyrimido[1,2-b]indazole skeleton was developed through selective cyclization of an in situ generated enone intermediate and 1H-indazol-3-amine. The one-pot, metal-free process formed three C–N bonds, one C–C bond, and a tetrasubstituted carbon stereocenter containing a hydroxyl group. This method not only allowed for the synthesis of over 60 new pyrrolidone fused pyrimido[1,2-b]indazole derivatives, but was also compatible with the transformation of complex active molecules and the derivation of target products. Significantly, product 4q exhibited aggregation-induced emission (AIE) characteristics without any further modification. [ABSTRACT FROM AUTHOR]

A novel process using N-benzylhydroxylamine hydrochloride as a "C1N1 synthon" in [2+2+1] cyclization for the construction of 1,2,5-trisubstituted imidazoles has been described for the first time. The key to realizing this process lies in capturing arylamines by in situ generated novel acyl ketonitrone intermediates. Subsequent tautomerization activates the α-C(sp3)–H of N-benzylhydroxylamines, and thus breaks through its inherent reaction mode and achieves N, α-C site-selective cyclization. Furthermore, this method enables scale-up synthesis and late-stage modification of complex molecules. [ABSTRACT FROM AUTHOR]

An efficient I2/CuCl2-promoted one-pot three-component strategy for the construction of 1,2,3-thiadiazoles from aliphatic- or aromatic-substituted methyl ketones, p-toluenesulfonyl hydrazide, and potassium thiocyanate has been developed. Simple and commercially available starting materials, a broad substrate scope, and excellent functional group tolerability make this strategy practical for applications. Furthermore, 1,2,3-thiadiazole synthesis was realized by using potassium thiocyanate as an odorless sulfur source. [ABSTRACT FROM AUTHOR]

An efficient method for constructing 2-acyl-3-aminoindoles from methyl ketones and 2-aminobenzonitriles is described, in which NaHS·nH2O is used as a novel umpolung reagent for the first time in organic synthesis. Mechanistic studies revealed that the key step involved an Eschenmoser sulfide contraction reaction. [ABSTRACT FROM AUTHOR]

An I2-promoted formal [3+2] cycloaddition for access to oxazoles has been demonstrated. This is the first example of a Lewis acid-promoted formal [3+2] cycloaddition of isocyanides with methyl ketones involving the C≡N cleavage of isocyanides. The salient feature of this approach is unconventional 2,5-disubstituted oxazole formation from isocyanides and ketones rather than 4,5-substituted oxazoline. [ABSTRACT FROM AUTHOR]

An efficient transition-metal-free cascade reaction has been developed for the facile synthesis of 12H-benzo[4,5]thiazolo[2,3-b]quinazolin-12-one derivatives from commercially available isatins and 2-haloaryl isothiocyanates. A preliminary mechanistic study suggested an interrupted Dimroth rearrangement was the key step for the successful transformation. [ABSTRACT FROM AUTHOR]

An unprecedented use of trifluoromethanesulfonyl hydrazides as effective SCF3 sources has been established in the sulfenylation of indoles. A range of substituted indoles participated in CuCl-catalyzed oxidative sulfenylation reaction with TfNHNHBoc in the presence of dimethyl sulfoxide to furnish structurally diverse 3-indolyl trifluoromethyl thioethers in moderate to good yields with very high regioselectivity. [ABSTRACT FROM AUTHOR]

A noncovalent macrocycle-within-noncovalent macrocycle assembly is formed from twelve molecules of (±)-1and twelve molecules of MeOH in the solid state. The H-bonded (MeOH)12cyclododecamer assumes a crown-shaped geometry that has not previously been predicted theoretically or found experimentally. [ABSTRACT FROM AUTHOR]