A convenient synthesis of 1′-H-spiro-(indoline-3,4′-piperidine) and its derivatives

Harnessing interrupted Fischer in continuous flow: sustainable synthesis of (spiro)indolenine and (spiro)indoline privileged scaffolds

3,3-Disubstituted indolenines are obtained via a green and sustainable flow chemistry protocol for interrupted Fischer indolisation reactions.

Dialkylation of Indoles with Trichloroacetimidates to Access 3,3-Disubstituted Indolenines

2-Substituted indoles may be directly transformed to 3,3-dialkyl indolenines with trichloroacetimidate electrophiles and the Lewis acid TMSOTf. These reactions provide rapid access to complex indolenines which are present in a variety of complex natural products and medicinally relevant small molecule structures. This method provides an alternative to the use of transition metal catalysis. The indolenines are readily transformed into spiroindoline systems which are privileged scaffolds in medicinal chemistry.

Conformationally constrained ortho-anilino diaryl ureas: discovery of 1-(2-(1'-neopentylspiro[indoline-3,4'-piperidine]-1-yl)phenyl)-3-(4-(trifluoromethoxy)phenyl)urea, a potent, selective, and bioavailable P2Y1 antagonist

Preclinical antithrombotic efficacy and bleeding models have demonstrated that P2Y1 antagonists are efficacious as antiplatelet agents and may offer a safety advantage over P2Y12 antagonists in terms of reduced bleeding liabilities. In this article, we describe the structural modification of the tert-butyl phenoxy portion of lead compound 1 and the subsequent discovery of a novel series of conformationally constrained ortho-anilino diaryl ureas. In particular, spiropiperidine indoline-substituted diaryl ureas are described as potent, orally bioavailable small-molecule P2Y1 antagonists with improved activity in functional assays and improved oral bioavailability in rats. Homology modeling and rat PK/PD studies on benchmark compound 3l will also be presented. Compound 3l was our first P2Y1 antagonist to demonstrate a robust oral antithrombotic effect with mild bleeding liability in the rat thrombosis and hemostasis models.

Electrophile-induced dearomatizing spirocyclization of N-arylisonicotinamides: a route to spirocyclic piperidines

Treatment of N-arylisonicotinamides with trifluoromethanesulfonic anhydride triggers intramolecular nucleophilic attack of the aryl ring on the 4-position of the pyridinium intermediate. The products are spirocyclic dihydropyridines which can be converted to valuable spirocyclic piperidines related to biologically active molecules such as MK-677.

Potent, nonpeptide inhibitors of human mast cell tryptase. Synthesis and biological evaluation of novel spirocyclic piperidine amide derivatives

We have explored a series of spirocyclic piperidine amide derivatives (5) as tryptase inhibitors. Thus, 4 (JNJ-27390467) was identified as a potent, selective tryptase inhibitor with oral efficacy in two animal models of airway inflammation (sheep and guinea pig asthma models). An X-ray co-crystal structure of 4 x tryptase revealed a hydrophobic pocket in the enzyme's active site, which is induced by the phenylethynyl group and is comprised of amino acid residues from two different monomers of the tetrameric protein.

Synthesis of highly functionalised spiro-indoles by a halogen atom transfer radical cyclization

The halogen atom transfer radical cyclization (HATRC) has been evaluated on N-(indolylmethyl)trichloroacetamides under Cu(I)Cl catalysis using nitrogen containing ligands. The ring closure leads to the formation of 3,3-spiro-3H-indoles in moderate to good yields by a 5-exo-mechanism. Derivatives with an N-electron withdrawing substituent also lead to a 5-exo-trig and not to a 6-endo-trig cyclization.