Dual Inhibition of Mycobacterium tuberculosis and the Host TGFBR1 by an Anilinoquinazoline.

Tuberculosis (TB) control is complicated by the emergence of drug resistance. Promising strategies to prevent drug resistance are the targeting of nonreplicating, drug-tolerant bacterial populations and targeting of the host, but inhibitors and targets for either are still rare. In a cell-based screen of ATP-competitive inhibitors, we identified compounds with in vitro activity against replicating Mycobacterium tuberculosis (Mtb), and an anilinoquinazoline (AQA) that also had potent activity against nonreplicating and persistent Mtb. AQA was originally developed to inhibit human transforming growth factor receptor 1 (TGFBR1), a host kinase that is predicted to have host-adverse effects during Mtb infection. The structure-activity relationship of this dually active compound identified the pyridyl-6-methyl group as being required for potent Mtb inhibition but a liability for P450 metabolism. Pyrrolopyrimidine (43) emerged as the optimal compound that balanced micromolar inhibition of nonreplicating Mtb and TGFBR1 while also demonstrating improved metabolic stability and pharmacokinetic profiles.

Directed Photochemically Mediated Nickel-Catalyzed (Hetero)arylation of Aliphatic C-H Bonds.

Site-selective functionalization of unactivated C(sp3)-H centers is challenging because of the ubiquity and strength of alkyl C-H bonds. Herein, we disclose a position-selective C(sp3)-C(sp2) cross-coupling reaction. This process engages C(sp3)-H bonds and aryl bromides, utilizing catalytic quantities of a photoredox-capable molecule and a nickel precatalyst. Using this technology, selective C-H functionalization arises owing to a 1,6-hydrogen atom transfer (HAT) process that is guided by a pendant alcohol-anchored sulfamate ester. These transformations proceed directly from N-H bonds, in contrast to previous directed, radical-mediated, C-H arylation processes, which have relied on prior oxidation of the reactive nitrogen center in reactions with nucleophilic arenes. Moreover, these conditions promote arylation at secondary centers in good yields with excellent selectivity.

Strategies to Generate Nitrogen-centered Radicals That May Rely on Photoredox Catalysis: Development in Reaction Methodology and Applications in Organic Synthesis.

For more than 70 years, nitrogen-centered radicals have been recognized as potent synthetic intermediates. This review is a survey designed for use by chemists engaged in target-oriented synthesis. This review summarizes the recent paradigm shift in access to and application of N-centered radicals enabled by visible-light photocatalysis. This shift broadens and streamlines approaches to many small molecules because visible-light photocatalysis conditions are mild. Explicit attention is paid to innovative advances in N-X bonds as radical precursors, where X = Cl, N, S, O, and H. For clarity, key mechanistic data is noted, where available. Synthetic applications and limitations are summarized to illuminate the tremendous utility of photocatalytically generated nitrogen-centered radicals.

Ring-Opening Lithiation-Borylation of 2-Trifluoromethyl Oxirane: A Route to Versatile Tertiary Trifluoromethyl Boronic Esters.

Stereogenic trifluoromethyl-substituted carbon centers are highly sought-after moieties in pharmaceutical and agrochemical discovery. Here, we show that lithiation-borylation reactions of 2-trifluoromethyl oxirane give densely functionalized and highly versatile trifluoromethyl-substituted α-tertiary boronic esters. The intermediate boronate complexes undergo the desired 1,2-rearrangement of the carbon-based group with complete retentive stereospecificity, a process that was only observed in non-polar solvents in the presence of TESOTf. Although the trifluoromethyl group adversely affects subsequent transformations of the α-boryl group, Zweifel olefinations provide trifluoromethyl-bearing quaternary stereocenters substituted with alkenes, alkynes and ketones.

Enantiodivergent Synthesis of Allenes by Point-to-Axial Chirality Transfer.

An enantiodivergent method for the synthesis of multiply substituted allenes is described. Highly enantioenriched, point-chiral boronic esters were synthesized by homologation of α-seleno alkenyl boronic esters with lithiated carbamates and eliminated to form axially chiral allene products. By employing either oxidative or alkylative conditions, both syn and anti elimination could be achieved with complete stereospecificity. The process enables the synthesis of either M or P allenes from a single isomer of a point-chiral precursor and can be employed for the enantioselective assembly of di-, tri-, and tetrasubstituted allenes.

Crystal structures of three 1-oxo-1,2-di-hydro-naphthalene derivatives: dimethyl 4-(4-meth-oxy-phen-yl)-2-(4-methyl-phen-yl)-1-oxo-1,2-di-hydro-naphthalene-2,3-di-carboxyl-ate, dimethyl 1-oxo-2-(pyren-4-yl)-4-(thio-phen-2-yl)-1,2-di-hydro-naphthalene-2,3-di-carboxyl-ate and ethyl 1-oxo-2-phenyl-2,4-bis-(thio-phen-2-yl)-1,2-di-hydro-naphthalene-3-carboxyl-ate.

In the title 1-oxo-1,2-di-hydro-naphthalene derivatives, C28H24O6, (I), C34H22O5S, (II), and C27H20O3S2, (III), the cyclo-hexa-1,3-diene rings of the 1,2-di-hydro-naphthalene ring systems adopt half-chair, boat and half-chair conformations, respectively. The carbonyl O atoms attached to the di-hydro-naphthalene ring systems are each significantly deviated from the mean plane of the 1,2-di-hydro-naphthalene ring system, by 0.6162 (12) Šin (I), 0.6016 (16) Šin (II) and 0.515 (3) Šin (III). The mean planes of the 1,2-di-hydro-naphthalene ring systems make dihedral angles of 85.83 (3), 88.19 (3) and 81.67 (8)°, respectively, with the methyl-phenyl ring in (I), the pyrene ring in (II) and the phenyl ring in (III). In (I), the mol-ecular structure is stabilized by an intra-molecular C-H⋯O hydrogen bond, generating an S(6) ring motif. In the crystal of (I), mol-ecules are linked by an inter-molecular C-H⋯O hydrogen bond, which generates a C(8) zigzag chain running along [100]. Adjacent chains are further connected by C-H⋯π and offset π-π inter-actions [centroid-centroid distance = 3.6572 (9) Å], forming a double-chain structure. In the crystals of (II) and (III), mol-ecules are linked into chain structures by offset π-π inter-actions with centroid-centroid distances of 3.5349 (12) and 3.8845 (13) Šfor (II) and 3.588 (2) Šfor (III). In (II) and (III), the thio-phene rings are orientationally disordered over two sites, with occupancy ratios of 0.69:0.31 for (II), and 0.528 (4):0.472 (4) and 0.632 (5):0.368 (5) for (III).

Synthetic transformation of 1,3-diarylisobenzofuran-DMAD adducts: a facile preparation of tri-substituted α-naphthols.

1,3-Diarylisobenzofuran-DMAD adducts upon reaction with BF3·OEt2 in DCM at room temperature underwent a regiospecific 1,2-aryl migration followed by the Krapcho decarboxylation to give tri-substituted α-naphthols in good yields.

Crystal structures and conformations of two Diels-Alder adduct derivatives: 1,8-bis-(thio-phen-2-yl)-14-oxa-tetra-cyclo-[6.5.1.0(2,7).0(9,13)]tetra-deca-2(7),3,5-trien-10-one and 1,8-diphenyl-14-oxa-tetra-cyclo[6.5.1.0(2,7).0(9,13)] tetra-deca-2,4,6-trien-10-one.

The title compounds, C21H16O2S2 (I) and C25H20O2 (II), are products of a tandem 'pincer' Diels-Alder reaction consisting of [2 + 2] cyclo-additions between benzo[c]furan and cyclo-penta-none. Each comprises a fused tetra-cyclic ring system containing two five-membered rings (in envelope conformations with the O atom as the flap) and six-membered rings (in boat conformations). In addition, two thio-phene rings in (I) and two phenyl rings in (II) are attached to the tetra-cyclic ring system. The cyclo-penta-none ring adopts a twisted conformation in (I) and an envelope conformation in (II). In (I), the thio-phene rings are positionally disordered over two sets of sites, with occupancy ratios of 0.901 (2):0.099 (2) and 0.666 (2):0.334 (2). In (II), the oxygen atom of the cyclo-penta-none ring is rotationally disordered over two sites with an occupancy ratio of 0.579 (4):0.421 (4). The mol-ecular structure of (I) is stabilized by an intra-molecular C-H⋯O hydrogen bond, which generates an S(7) ring motif. In the crystal, the mol-ecules are linked via weak C-H⋯O hydrogen bonds, which generate R (2) 2(16) ring motifs in (I) and C(8) chains in (II). In both structures, the crystal packing also features C-H⋯π inter-actions. The crystal studied of compound (I) was twinned by non-merohedry. The twin component is related by the twin law [-1 0 0 -0.101 1 -0.484 0 0 -1] operated by a twofold rotation axis parallel to the b axis. The structure of (I) was refined with a twin scale factor of 0.275 (2).

Crystal structure of 2,9-diphenyl-17λ(6)-thia-tetra-cyclo-[8.7.0.0(3,8).0(11,16)]hepta-deca-1(10),2,4,6,8,11(16),12,14-octa-ene-17,17-dione.

The title compound, C28H18O2S, is composed of a naphthalene ring system fused with a benzo-thio-phene ring and attached to two phenyl rings. The phenyl rings make dihedral angles of 70.92 (8) and 79.23 (8)° with the essentially planar naphthalene ring system (r.m.s. deviation = 0.031 Å). There is an intra-molecular C-H⋯π inter-action present. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds which generate C(7) zigzag chains running parallel to [10-1]. The chains are linked via further C-H⋯π inter-actions, forming a three-dimensional structure.

3,10,14,21-Tetra-kis(4-meth-oxy-phen-yl)penta-cyclo-[11.8.0.0(2,11).0(4,9).0(15,20)]henicosa-1(21),2,4(9),5,7,10,13,15(20),16,18-decaen-12-one chloro-form monosolvate.

The asymmetric unit of the title compound, C49H36O6·CHCl3, contains half an organic mol-ecule, the complete mol-ecule being generated by the operation of a crystallographic twofold rotation axis, and half a highly disordered chloro-form mol-ecule. The contribution to the diffraction pattern of the latter was removed using the program SQUEEZE in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148-155]; the unit-cell characteristics take into account the presence of CHCl3. The dihedral angles between the planes of the naphthalene ring system and the meth-oxy-benzene rings are 71.05 (7) (syn to the central C=O group) and 57.27 (6)° (anti to the central C=O group). In the crystal, mol-ecules are linked by C-H⋯O inter-actions, generating C(12) chains running parallel to the b axis.

Diels-Alder reaction of 1,3-diarylbenzo[c]furans with thiophene S,S-dioxide/indenone derivatives: a facile preparation of substituted dibenzothiophene S,S-dioxides and fluorenones.

One pot syntheses of substituted dibenzothiophene S,S-dioxides and fluorenones were successfully achieved by Diels-Alder reaction of benzo[c]furans with thiophene S,S-dioxides and indenones, respectively. Photophysical properties of representative seven- and nine-membered dibenzothiophene S,S-dioxide acenes were also reported.

Dimethyl 1,8-bis-(4-methyl-phen-yl)-11-oxatri-cyclo-[6.2.1.0(2,7)]undeca-2,4,6,9-tetra-ene-9,10-di-carboxyl-ate.

The title compound, C28H24O5, consists of a fused tricyclic system containing two five-membered rings and one six-membered ring. The five-membered rings both exhibit an envelope conformation with the O atom at the flap, whereas the six-membered ring adopts a boat conformation. The dihedral angle between the 4-methyl-phenyl rings at the 1,8-positions is 76.4 (1)°. In the crystal, mol-ecules are stacked in columns along the a axis through C-H⋯O inter-actions.

Dimethyl 1-(4-methyl-phen-yl)-8-(thio-phen-2-yl)-11-oxatricyclo-[6.2.1.0(2,7)]undeca-2,4,6,9-tetra-ene-9,10-dicarboxy-late.

The title compound, C25H20O5S, is the product of a Diels-Alder reaction. The mol-ecule consists of a fused tricyclic system containing two five-membered rings and one six-membered ring. The five-membered rings both show an envelope conformation with the O atom at the flap, whereas the six-membered ring adopts a boat conformation. The thio-phene ring is disordered over two sets of sites with an occupancy ratio of 0.53 (1):0.47 (1). The dihedral angles between the 4-methyl-phenyl ring and the major and minor components of the thio-phene ring are 66.3 (1) and 67.9 (1)°, respectively, while the dihedral angle between the disordered thio-phenyl components is 3.1 (1)°. The mean plane of the tricyclic ring system makes dihedral angles of 35.8 (1), 30.8 (1) and 32.8 (1)°, respectively, with the 4-methyl-phenyl ring and the major and minor components of the thio-phenyl ring. In the crystal, inversion dimers are formed through pairs of C-H⋯π inter-actions. In addition, C-H⋯O inter-actions are observed.

Diethyl 1,8-bis-(4-methyl-phen-yl)-11-oxatricyclo-[6.2.1.0(2,7)]undeca-2,4,6-triene-9,10-dicarboxyl-ate.

The title compound, C30H30O5, is the Diels-Alder adduct from 1,3-diphenyl-benzo[c]furan and diethyl maleate. The mol-ecule comprises a fused tricyclic system containing two five-membered rings, which are in envelope conformations with the O atom at the flap, and a six-membered ring adopting a boat conformation. The dihedral angle between the 4-methyl-phenyl substituents in the 1- and 8-positions is 62.1 (1)°. The ethyl group of one ester group and the eth-oxy group of the other ester group are disordered over two sets of sites, with occupancy ratios of 0.43 (2):0.57 (2) and 0.804 (7):0.196 (7), respectively. In the crystal, inversion dimers are formed through pairs of C-H⋯O inter-actions.

Diethyl 1,8-diphenyl-11-oxatricyclo-[6.2.1.0(2,7)]undeca-2,4,6-triene-9,10-dicarboxyl-ate.

The title compound, C28H26O5, is the Diels-Alder adduct from 1,3-diphenyl-benzo[c]furan and diethyl maleate. The mol-ecule comprises of a fused tricyclic system containing two five-membered rings, which are in envelope conformations with the O atom at the flap, and a six-membered ring adopting a boat conformation. The dihedral angle between phenyl substituents in the 1,8-positions is 55.1 (1)°. The ethyl groups are disordered over two sets of sites, with occupancy ratios of 0.648 (9):0.352 (9) and 0.816 (1):0.184 (1). In the crystal, pairs of C-H⋯π inter-actions link the mol-ecules into inversion dimers.

Synthesis of annulated arenes and heteroarenes involving Lewis acid-mediated regioselective annulation of unsymmetrical 1,2-(diaryl/diheteroarylmethine)dipivalates.

A ZnBr(2)-mediated regioselective annulation of unsymmetrical 1,2-diarylmethinedipivalates in DCM at room temperature led to the formation of annulated arenes and heteroarenes. The annulation of the dipivalate proceeds through the intermediacy of benzylic carbocations followed by intramolecular cyclization and subsequent aromatization to give the annulated products. The annulation methodology is highly efficient for the syntheses of anthracene as well as naphtho[b]thiophene analogues.

{2-[(9,9-Dihexyl-fluoren-2-yl)carbon-yl]phen-yl}(4-meth-oxy-phen-yl)methanone.

In the title compound, C(40)H(44)O(3), the fluorene ring system is essentially planar, with a maximum deviation of 0.075 (3) Å, and forms dihedral angles of 70.62 (8) and 70.31 (8)° with the mean planes of the central benzene ring and the meth-oxy-phenyl ring, respectively. Both the hexyl side chains have different conformations, i.e. an anti-gauche-anti-gauche conformation with C-C-C-C torsion angles of -169.3 (2), 74.2 (4), -178.0 (3) and -76.0 (6)° for one hexyl side chain and an anti-anti-anti-gauche conformation with C-C-C-C torsion angles of -177.9 (2), -176.5 (3), 171.7 (4) and 80.4 (9)° for the other. Four C atoms in one and two C atoms in the other hexyl side chains are each disordered over two sets of sites, with occupancy factors of 0.761 (3):0.239 (3) and 0.660 (6):0.340 (6). In the crystal, mol-ecules are via pairs of C-H⋯O hydrogen bonds, forming inversion dimers and resulting in R(2) (2)(28) graph-set motifs.

[2-(4-Methylbenzoyl)phenyl](4-methylphenyl)methanone.

The asymmetric unit of the title compound, C(22)H(18)O(2), contains one half-mol-ecule, the complete mol-ecule being generated by the operation of a crystallographic twofold rotation axis. The carbonyl group and the two C atoms attached to it forms inter-planar angles of 23.67 (7)° with the methyl-substituted phenyl ring and 50.74 (8)° with the central ring. In the crystal, mol-ecules are linked into infinite chains along the b-axis direction by inter-molecular C-H⋯O inter-actions, generating R(2) (2)(10) graph-set motifs.

[3-Hy-droxy-methyl-1,4-bis-(4-methyl-phen-yl)naphthalen-2-yl]methanol.

In the title compound, C(26)H(24)O(2), the crowded naphthalene ring system is essentially planar [maximum deviation of 0.027 (2) Šfor one of the C atoms of the unsubstituted ring]. In the crystal, mol-ecules are connected by O-H⋯O hydrogen bonds into chains along the a axis. Pairs of the oppositely oriented chains are further cross-linked by O-H⋯O hydrogen bonds, forming infinte bands of alternating R(4) (4)(8) dimers and R(2) (2)(14) motifs.

Lewis acid-mediated Michaelis-Arbuzov reaction at room temperature: a facile preparation of arylmethyl/heteroarylmethyl phosphonates.

A facile preparation of arylmethyl and heteroarylmethyl phosphonate esters was achieved involving a Lewis acid mediated Michaelis-Arbuzov reaction at room temperature. Interaction of arylmethyl halides/alcohols with triethyl phosphite in the presence of Lewis acid at room temperature afforded phosphonate esters in good yields.