Congratulations to Mahesh @MaheshHarariya on successfully defending his PhD thesis! We sincerely thank Prof. R. B. Sunoj @sunojchemlab for graciously conducting the in-person thesis viva at @iiscbangalore, & Prof. Dean Tantillo @TantilloLab for his thorough review of the thesis.

Congratulations to Ritwika @chatt_ritwika on successfully defending her PhD thesis! We sincerely thank Prof. Ankan Paul for graciously conducting the viva voce examination, and Prof. Dean Tantillo @TantilloLab for his thorough and meticulous review of the thesis.

Congratulations to Reena @balhara_reena on successfully defending her PhD thesis! We sincerely thank Prof. Kumar Vanka @KumarVanka1 for graciously conducting the in-person thesis viva at @iiscbangalore, and Prof. Dean Tantillo @TantilloLab for his thorough review of the thesis.

An account detailing our research on metal-associated enols as key intermediates in controlling enantioselectivity in carbene insertion reactions is now available online. Congratulations @DevDodiya2 @MaheshHarariya ! thieme-connect.com/products/…

Most importantly, it was uncovered that the orientation of the metallocarbene and therefore, the stereochemical outcome of the reaction, was determined by the precise location of hydrogen bond donor residues at the active site - this is essentially found to be the key... (9/n)

Next, with the mechanism established, we used a combination of MD and the QM cluster approach to probe the stereocontrol of the stereocomplementary mutants at the active sites. The HAT was found to be stereodetermining with any subsequent stereoablation being ruled out. (8/n)

First, using a smaller sized model system to mimic the active site of the P411 variants, we examined (using DFT) various mechanistic possibilities and determined that a hydrogen atom transfer (HAT) followed by a concerted radical rebound was the most feasible pathway. (7/n)

...stereodivergent (and particularly, enantiodivergent) carbene transfer reactions. In one such protocol for the enantiodivergent synthesis of beta-amino lactone, intriguingly, two such mutants differing by a single (!) mutation were found to show opposite stereoprefence. (5/n)

In this context of biocatalysis, directed evolution offers the unique opportunity to efficiently design enzymes for stereodivergent synthesis. Serine-ligated variants of cytochrome P450, "P411" variants, developed by @francesarnold, have been found to catalyze various... (4/n)

However, since enzymes are hardly ever available in enantiomeric forms (although select examples of enantiocomplementary enzymes exist), it is challenging to separately access both stereoisomeric molecules through enzymatic catalysis. (3/n)