Our primary research revolves around the 'development of green organometallic reagents and their applications to organic synthesis'. We embarked upon the development of 'new generation cross-coupling reactions' using triarylbismuths as 3-fold coupling reagents. Over the years, we have developed a variety of new coupling reactions using organobismuth chemistry, with a diverse range of reactivity under palladium catalyzed conditions with high atom-economy. Further research activities in our group include convergent organic synthesis, microwave mediated organic synthesis, auto-catalysis, metal catalyzed reactions and other reactions of contemporary interest.

New Generation Green Cross-Coupling Reactions: Cross-coupling methods have enriched the art of organic synthesis and evolved as effective synthetic tools to construct complex molecular systems. The well-known coupling reactions such as Suzuki, Stille, Negeshi, etc. invariably involve only one C-C bond formation (eq. 1). 

We envisaged that a paradigm shift in the reagent capability is necessary to make these reactions more green and atom-economic with additional potential for multi C-C couplings in one-pot operation.

Triarylbismuths, which are non-toxic, air stable, and contain three aryl groups (e.g., Figure 1), appeared to us as the most promising green organometallic reagents with 3-fold coupling capabilities (eq.2). 

These reagents could, in principle, be employed in sub-stoichiometric 1/3 molar equivalents with increased atom-efficiency in a one-pot operation (eq. 2 vs eq. 1). Our consistent efforts have led to the development of new generation cross-coupling reactions with triarylbismuths reagents, and opened up a plethora of new opportunities in terms of reactivity and selectivity.  Thus, a new series of Pd-catalyzed coupling reactions have been developed involving aryl, heteroaryl, acyl, allyl and vinyl couplings, bis-couplings,  carbonylations and domino one-pot coupling reactions.

• Pd-catalyzed chemoselective threefold cross-coupling of triarylbismuths with benzylic bromides,
  RSC Advances, 13, 6794 (2013)

• Pd-Catalyzed Tandem Chemo-selective Synthesis of 2-Arylbenzo- furans using Threefold Arylating Triarylbismuth Reagents, 
  Eur. J. Org. Chem., 781 (2013)

• Pd-catalyzed threefold arylations of mono, di and tetra-bromoquinones using triarylbismuth reagents,      
  RSC Advances, 12, 12739 (2012)

• Transition-metal catalyzed C-C bond formation using organobismuth compounds,
  Top. Curr. Chem., 311, 199 (2012)

• Synthesis of functionalized 2-aryl-thiophenes with triarylbismutorganometallic nucleophiles under palladium catalysis, 
  Syn. Lett., 1324 (2011)

• Pd(0)-catalyzed couplings using bromide and chloride derivatives of Baylis–Hillman adducts with triarylbismuths as atom-efficient multi-coupling nucleophiles, Tetrahedron, 66, 3623 (2010)

• Pd-catalyzed domino synthesis of internal alkynes using triarylbismuths as multicoupling organometallic nucleophiles,
  Org. Lett., 12, 2048 (2010)

• IIT Kanpur, 2003-

• University of North Carolina (UNC) Chapel Hill, USA, 2002-2003

• Post Doc at NIMC, NIAR and  AIST, Tsukuba, JAPAN, 1997-2002

• CREST  Fellow  (JST, JAPAN), 1997-2000

Office

CL 204E/ Core Labs ,
Department of Chemistry
IIT Kanpur,
Kanpur 208016

Office Phone: 0512-259-7163 / 7532 (O)

Email: maddali[AT]iitk.ac.in