His research interests include Organophosphorus Chemistry and Main Group Chemistry. He has over 115 publications so far and is a fellow of the Indian Academy of Sciences, Bangalore. N. N. Bhuvan Kumar was born in Cherukupalli, Guntur, India. After completing his B.Sc. from Nagarjuna University, he joined the School of Chemistry, University of Hyderabad, as a postgraduate student in the year 2000 and obtained his Master's degree in Chemistry. Currently, he is pursuing a Ph.D. on Organophosphonates under the supervision of Prof. K. C. Kumara Swamy. E. Balaraman was born in Kancheepuram, Chennai, India, in 1980. He received his M.Sc. in Chemistry from Vivekananda College [Madras University (2002)] and his Ph.D. degree in the areas of organophosphonates and modified BINOLs under the guidance of Prof. K. C. Kumara Swamy. Presently he is a postdoctoral fellow with Professors David Milstein and Ronny Neumann at the Weizmann Institute of Science, Israel. K. V. P. Pavan Kumar was born in Hyderabad (Andhra Pradesh), India, in 1979. He obtained his B.Sc. (Chemistry Honors) and M.Sc. (Chemistry) degrees from Sri Sathya Sai Institute of Higher Learning, Puttaparthi, A.P., India. He obtained his Ph.D. degree under the guidance of Prof. K. C. Kumara Swamy in October 2006. Presently he is working as a postdoctoral fellow in the area of hydroamination reactions using new titanium catalysts with Prof. Pierre Le Gendre at the Universite ´de Bourgogne, France.

Coupling reactions of allenylphosphonates (OCH(2)CMe(2)CH(2)O)P(O)CH=C=CRR' [R, R' = H (1a), R = H, R' = Me (1b), R = R' = Me (1c)] with aryl iodides, iodophenol, and iodobenzoic acid in the presence of palladium(II) acetate are investigated and compared with those of phenylallenes PhCH=C=CR2 [R = H (2a), Me (2b)] and allenyl esters EtO(2)CCH=C=CR(2) [R = H (2c), Me (2d)]. While 1b and 1c couple with different stereochemical outcomes using PhI in the presence of Pd(OAc)(2)/PPh(3)/K(2)CO(3) to give phenyl-substituted 1,3-butadienes, 1a does not undergo coupling but isomerizes to the acetylene (OCH(2)CMe(2)CH(2)O)P(O)CCMe (7). In the reaction of 1c with PhI, use of K(2)CO(3) affords the butadiene (Z)-(OCH(2)CMe(2)CH(2)O)P(O)CH=C(Ph)-C(Me)=CH(2) (12); in contrast, the use of Ag(2)CO(3) leads to the allene (OCH(2)CMe(2)CH(2)O)P(O)C(Ph)=C=CMe(2) (20), showing that these bases differ very significantly in their roles. The reaction of 1a with PhI or PhB(OH)2 in (t)he presence of Pd(OAc)2/CsF/DMF leads mainly to (E)-(OCH(2)CMe(2)CH(2)O)P(O)CH=C(Me)Ph (21) and (OCH(2)CMe(2)CH(2)O)P(O)CH2-C(Ph)=CH(2) (22) and is thus a net 1,2-addition of Ph-H. Compound 1b reacts with iodophenol in the presence of Pd(OAc)(2)/PPh(3)/K(2)CO(3) to give a benzofuran that has a structure different from that obtained by using 1c under similar conditions. Treatment of 1a with iodophenol/Pd(OAc)(2)/CsF/DMF also gives a benzofuran whose structure is different from that obtained by using 2a under similar conditions. In the reaction with 2-iodobenzoic acid, 1a and 2c afford one type of isocoumarin, while 1b,c and 2a,b give a second type of isocoumarin. The structures of key compounds are established by X-ray crystallography. Utility of the phosphonate products in the Horner-Wadsworth-Emmons reaction is demonstrated.

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The novel macrocyclic compounds {(OCH2CMe2CH2O)[(S)PN-t-Bu]2}2 (4) and {(OCH2CMe2CH2O)[P(N-t-Bu)2P(1,2-O2C6Cl4)]}2·3C6H5CH3 (5·3C6H5CH3) based on the cyclodiphosphazane unit are synthesized and characterized by X-ray structure determination; their solution state NMR spectra are consistent with the solid state structures.

Ruthenium-catalyzed oxidative annulation of N-quinolin-8-yl-benzamides with alkynes in open air has been achieved using 8-aminoquinolinyl moiety as a bidentate directing group in the presence of Cu(OAc)2·H2O as an oxidant. This reaction offers a broad substrate scope, and both symmetrical and unsymmetrical alkynes can be applied. High regioselectivity was achieved in the case of unsymmetrical (aryl)alkynes. Reaction with heteroaryl amides was also successful in this catalytic process. A ruthenium-N-quinolin-8-yl-benzamide complex was isolated in the absence of alkyne; in the absence of both N-quinolin-8-yl-benzamide and alkyne, in contrast to literature, only the monoacetate complex RuCl(OAc)(p-cymene), but not the bis-acetate complex Ru(OAc)2(p-cymene), was isolated. These data suggest that this reaction may proceed via N,N-bidentate chelate complex. Key products were characterized by X-ray crystallography.