Gao and coworkers have reported that on reacting 2-FPBA and 2-APBA with L-cysteine in 0.10 M phosphatebuffered saline (PBS) buffer at physiological pH, bicyclic or tricyclic heterocycles form, which led to the survey of an array of borazaros and oxazaborons described herein (Fig. ); however, in this work such reactions exclusively furnished tetracyclic and heteroaromatic structures. Whilst almost all the diazaborines as well as boronate ester 12 described in this work have, one way or another, been reported in the literature, by all means, this work is a first-of-its-kind to delineate a 'tetracyclic caged' structure for novel boronate esters 11 & 13-18, and report full chemical characterisation i.e. mp, optical rotation, IR, NMR ( 1 H, 13 C & 11 B), LC-MS and HRMS of the aforementioned benzodiazaborines, diazaborines and novel boronate esters cf. ESI S4-S21 & S24-S26 † for which so far as this work is concerned there are no known precedents, and the specific applications, and of the broad implications of these intriguing heterocycles may, hopefully, be of interests to the synthetic and medicinal chemist alike.