SUBMITTED TO THE UNIVERSITY OF DELHI FOR THE AWARD OF THE DEGREE OF DOCTOR OF PHILOSOPHY

Reaction of alkyne allyl alcohols tethered with N-(p-tolylsulfonamide) in the presence of a cationic gold(I) catalyst gave new cycloisomerization products, 4-oxa-6-azatricyclo[3.3.0.0(2,8)]octanes.

Polymeric building blocks containing terminal azide and alkyne functionalities are prepared via atom transfer radical polymerization (ATRP) and used to modularly synthesize block copolymers via 1,3-dipolar cycloaddition reactions, which are quantitative according to SEC measurements.

We disclose a general two-step procedure to access hitherto unknown and under explored 5- 6-alkynyl-3-fluoro-2-pyridinamidoximes from 6-bromo-3-fluoro-2-cyanopyridines wide range of easily available bench-stable terminal alkynes, using Sonogashira cross-coupling, as the first step. The generation polar amidoxime group is realized at late stage upon treatment alkynylfluorocyanopyridine by hydrox...

A robust N-nucleophilic 1,3-N,O-dipole equivalent reacts with unsymmetrical internal alkynes under gold catalysis. Conjugation from a remote nitrogen lone pair enables and controls this convergent and highly regioselective process.

A rhodium-catalyzed carbene transfer to alkynes is reported. Easily available enynones served as the carbene source replacing diazocompounds. The overall process involved a cyclization-cyclopropenation-ring enlargement sequence.

A convenient Cu(I)-catalyzed cycloaddition of electron rich internal aryl alkynes and diazoacetates was discovered for the chemoselective and regioselective synthesis of tetra-substituted furans and cyclopropenes in moderate isolated yields (18-67%), and alkyne conversion (29-73%).

A novel method for visual detection of formaldehyde with excellent selectivity via a gold(iii) complex-mediated three-component coupling reaction of resin-linked sterically bulky amines and fluorescent alkynes has been developed.

The first direct intermolecular hydroamination/hydroalkylation of terminal alkynes catalyzed by In(OTf)(3) under one-pot conditions leading to the formation of conjugated ketimines in good yields is described.