Salim Javed

A Pot-Economical Approach to the Total Synthesis of Sch-725674

A pot-economical total synthesis of antifungal Sch-725674, 1, is reported. The approach takes advantage of a number of one-pot, sequential transformations, including a phosphate tether-mediated one-pot, sequential RCM/CM/chemoselective hydrogenation protocol, a one-pot tosylation/acrylation sequence, and a one-pot, sequential Finkelstein reaction/Boord olefination/acetonide deprotection procedure to streamline the synthesis route by reducing isolation and purification procedures, thus saving time. Overall, an asymmetric route has been developed that is efficiently accomplished in seven pots from phosphate (S,S)-triene and with minimal purification.

Automated synthesis of a library of triazolated 1,2,5-thiadiazepane 1,1-dioxides via a double aza-Michael strategy.

The construction of a 96-member library of triazolated 1,2,5-thiadiazepane 1,1-dioxides was performed on a Chemspeed Accelerator (SLT-100) automated parallel synthesis platform, culminating in the successful preparation of 94 out of 96 possible products. The key step, a one-pot, sequential elimination, double-aza-Michael reaction, and [3 + 2] Huisgen cycloaddition pathway has been automated and utilized in the production of two sets of triazolated sultam products.

Multicapillary Flow Reactor: Synthesis of 1,2,5-Thiadiazepane 1,1-Dioxide Library Utilizing One-Pot Elimination and Inter-/Intramolecular Double aza-Michael Addition Via Microwave-Assisted, Continuous-Flow Organic Synthesis (MACOS)

A microwave-assisted, continuous-flow organic synthesis (MACOS) protocol for the synthesis of functionalized 1,2,5-thiadiazepane 1,1-dioxide library, utilizing a one-pot elimination and inter-/intramolecular double aza-Michael addition strategy is reported. The optimized protocol in MACOS was utilized for scale-out and further extended for library production using a multicapillary flow reactor. A 50-member library of 1,2,5-thiadiazepane 1,1-dioxides was prepared on a 100- to 300-mg scale with overall yields between 50 and 80% and over 90 % purity determined by proton nuclear magnetic resonance (1H-NMR) spectroscopy.

Modular Synthesis of Novel Macrocycles Bearing α,β‐Unsaturated Chemotypes through a Series of One‐Pot, Sequential Protocols

A series of one-pot, sequential protocols was developed for the synthesis of novel macrocycles bearing α,β-unsaturated chemotypes. The method highlights a phosphate tether-mediated approach to establish asymmetry, and consecutive one-pot, sequential processes to access the macrocycles with minimal purification procedures. This library amenable strategy provided diverse macrocycles containing α,β-unsaturated carbon-, sulfur-, or phosphorus-based warheads.

Rapid, Scalable Assembly of Stereochemically Rich, Mono- and Bicyclic Acyl Sultams

A one-pot, sequential protocol is reported that involves complementary ambiphile pairing (CAP) of a vinyl sulfonamide with a variety of unprotected amino acids via aza-Michael addition and subsequent intramolecular amidation. The method generates diverse, sp(3)-rich mono- and bicyclic acyl sultams in a highly scalable manner. Modular pairing of stereochemically rich building blocks allows quick access to all possible isomers. Extension to include one-pot, sequential 3-, 4-, and 5-multicomponent protocols is also discussed.

Synthesis of the C9–C25 Subunit of Spirastrellolide B

The synthesis of the C9–C25 subunit of the marine natural product spirastrellolide B is reported. The key synthetic features included the union of the two key fragments 5 and 6 via a Suzuki–Miyaura coupling reaction and a late-stage, one-pot sequential deprotection/cascade Achmatowicz rearrangement–spiroketalization to install the key spirocyclic intermediate present in the C9–C25 fragment of spirastrellolide B. The synthesis of the C9–C16 fragment 6 was accomplished via a phosphate tether mediated ring-closing metathesis (RCM), a subsequent hydroboration–oxidation protocol, followed by other stereoselective transformations in a facile manner. The spirocyclic intermediate was further functionalized utilizing a Lindlar/NaBH4 reduction protocol to furnish the C9–C25 subunit 3.

Synthesis of P-, S-, Si-, B-, and Se-Heterocycles via Ring-Closing Metathesis

Heterocyclic compounds are an important class of motif in natural products and have found various applications in agriculture, pharmaceutical agents, and material science. This chapter describes various synthetic strategies toward heterocycle compounds containing P, S, Si, B, and Se atoms utilizing RCM method. Herein, efficient and innovative synthetic methods ranging from small molecules to large rings for natural products in the use of RCM are discussed.

Synthesis of a Library of 1,5,2-Dithiazepine 1,1-Dioxides. Part 2: Routes to Bicyclic Sultams.

The synthesis of a library of bicyclic sultams incorporating the 1,5,2-dithiazepine 1,1-dioxide moiety is reported. Following scaffold synthesis via a one-pot sulfonylation/intramolecular thia-Michael protocol, several additional cyclization strategies have been realized enabling access to new bicyclic sultams.

Synthesis of a Library of 1,5,2-Dithiazepine 1,1-Dioxides. Part 1: A One-Pot Sulfonylation/Thia-Michael Protocol

A novel one-pot sulfonylation/intramolecular thia-Michael protocol is reported for the synthesis of 1,5,2-dithiazepine 1,1-dioxides. Sulfonylation between cysteine ethyl ester/cysteamine and 2-chloroethanesulfonyl chloride, followed by in situ intramolecular thia-Michael addition, was achieved and afforded the titled 1,5,2-dithiazepine-1,1-dioxide scaffolds. Diversification was demonstrated for future library synthesis.