Functional Group Transformations

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Primary Amine ◽  
Simple Procedure ◽  
Primary Alcohol ◽  
Direct Conversion ◽  
Indian Institute ◽  
Chemical Technology ◽  
Amino Ester ◽  
Cu Catalyst ◽  
Ag Catalyst ◽  
The University

Jeffrey C. Pelletier of Wyeth Research, Collegeville, PA has developed (Tetrahedron Lett. 2007, 48, 7745) a easy work-up Mitsunobu procedure for the conversion of a primary alcohol such as 1 to the corresponding primary amine 2. Shlomo Rozen of Tel-Aviv University has taken advantage (J. Org. Chem. 2007, 72, 6500) of his own method for oxidation of a primary amine to the nitro compound to effect net conversion of an amino ester 3 to the alkylated amino ester 5. Note that the free amine of 3 or 5 would react immediately with methyl iodide. Keith A. Woerpel of the University of California, Irvine has uncovered (J. Am. Chem. Soc. 2007, 129, 12602) a Cu catalyst that, with 7, effected direct conversion of silyl ethers such as 6 to the allyl silane 8. An Ag catalyst gave 9, which also shows arllyl silane reactivity. Biswanath Das of the Indian Institute of Chemical Technology, Hyderabad has established (Tetrahedron Lett. 2007, 48, 6681) a compact procedure for the direct conversion of an aromatic aldehyde such as 10 to the benzylic halide 11. This will be especially useful for directly generating benzylic halides that are particularly reactive. α-Sulfinylation of ketones often requires intial generation of the enolate. J. S. Yadav, also of the Indian Institute of Chemical Technology, Hyderabad, has devised (Tetrahedron Lett. 2007, 48, 5243) an oxidative protocol for installing sulfur adjacent to a ketone. In a related development, Richard S. Grainger of the University of Birmingham has established (Angew. Chem. Int. Ed. 2007, 46, 5377) a simple procedure for the conversion of thio esters such as 14 to the corresponding ketone 16. Yoshiya Fukumoto of Osaka University has shown (J. Am. Chem. Soc. 2007, 129, 13792) that a terminal alkyne 17 can be directly converted into the enamine 18 by Rh-catalyzed addition of a secondary amine. Lukas Hintermann and Carsten Bolm of RWTH Aachen have found (J. Org. Chem. 2007, 72, 5704) that inclusion of water gave the aldehyde, which could be oxidized with the residual Ru catalyst to the acid.

Alkaloid Synthesis: Penaresidin A (Subba Reddy), Allokainic Acid (Saicic), Sedacryptine (Rutjes), Lepistine (Yokoshima/Fukuyama), Septicine (Hanessian), Lyconadin C (Dai)

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Marine Sponge ◽  
Indian Institute ◽  
Chemical Technology ◽  
Starting Material ◽  
Allylic Oxidation ◽  
Actomyosin Atpase ◽  
Alkaloid Synthesis ◽  
Purdue University ◽  
The University ◽  
Biogenetic Precursor

Penaresidin A 3, isolated from the Okinawan marine sponge Penares sp., is a potent activator of actomyosin ATPase. B. V. Subba Reddy of the Indian Institute of Chemical Technology prepared (Tetrahedron Lett. 2014, 55, 49) the azetidine ring of 3 by mesyl­ation of the hydroxy sulfonamide 2, derived from 1, followed by cyclization. Allokainic acid 6 has become a useful tool for neurological studies. Radomir N. Saicic of the University of Belgrade found (Org. Lett. 2014, 16, 34) that the Tsuji–Trost cyclization of 4 to 5 proceeded with high diastereoselectivity, presumably by way of the enamine of the aldehyde. Floris P. J. T. Rutjes of Radboud University Nijmegen prepared (Org. Lett. 2014, 16, 2038) the starting material 7 for (−)-sedacryptine 9 via an enantioselective Mannich addition. The reagent of choice for the Aza–Achmatowicz rearrangement of 7 to 8 proved to be mCPBA. The intriguing tricyclic alkaloid (−)-lepistine 12 was isolated from the mushroom Clitocybe fasciculate. En route to the first-ever synthesis of 12, Satoshi Yokoshima and Tohru Fukuyama of Nagoya University cyclized (Org. Lett. 2014, 16, 2862) the gly­cidol-derived sulfonamide 10 to the azacycle 11. (+)-Septicine 15 is the biogenetic precursor to the phenanthrene alkaloid (+)-tylophorine. Stephen Hanessian of the Université de Montréal prepared (Org. Lett. 2014, 16, 232) 15 by condensing the proline-derived ketone 13 with the aldehyde 14. Mingji Dai of Purdue University elaborated (Angew. Chem. Int. Ed. 2014, 53, 3922) the amine 16 to the enone 17 by intramolecular Mannich alkylation followed by methylenation and allylic oxidation. Condensation with the sulfoxide 18 then delivered lyconadin C 19.

Organic Functional Group Interconversion

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
New Orleans ◽  
Indian Institute ◽  
Unsaturated Aldehyde ◽  
Terminal Alkyne ◽  
Vinyl Ethers ◽  
Water Conditions ◽  
Cu Catalyst ◽  
Institute Of Technology ◽  
The University ◽  
Hydrolysis Of

Gojko Lalic of the University of Washington developed (Angew. Chem. Int. Ed. 2014, 53, 6473) conditions for the preparation of the fluoride 2 by SN2 displacement of the triflate 1. Ross M. Denton of the University of Nottingham showed (Tetrahedron Lett. 2014, 55, 799) that a polymer-bound phosphine oxide activated with oxalyl bromide would convert an alcohol 3 to the bromide 4. The polymer could be filtered off and reactivated directly. Jonas C. Peters and Gregory C. Fu of Caltech devised (J. Am. Chem. Soc. 2014, 136, 2162) a photochemically-activated Cu catalyst that mediated the displacement of the bromide 5 by the amide 6 to give 7. Mark L. Trudell of the University of New Orleans used (Synthesis 2014, 46, 230) an Ir catalyst to couple the amide 9 with the alcohol 8, leading to 10. Tohru Fukuyama of Nagoya University converted (Org. Lett. 2014, 16, 727) the unsaturated aldehyde 11 into the ester 12. As the transformation proceeded via proton­ation of the enolized acyl cyanide, the less stable diastereomer was formed kinetically. Brindaban C. Ranu of the Indian Association for the Cultivation of Science developed (Org. Lett. 2014, 16, 1040) conditions for the coupling of an alkenyl halide 13 with a phenol, leading to the vinyl ether 14. Inter alia, this would be a convenient way to hydrolyze an alkenyl halide to the aldehyde. Vinyl ethers can also be oxidized directly to the ester, and to the unsaturated aldehyde. Pallavi Sharma and John E. Moses of the University of Lincoln observed (Org. Lett. 2014, 16, 2158) that the cyanation of the alkenyl halide 15 delivered 16, with retention of the geometry of the alkene. Jitendra K. Bera of the Indian Institute of Technology Kanpur uncovered (Tetrahedron Lett. 2014, 55, 1444) “on water” conditions for the hydrolysis of a terminal alkyne 17 to the methyl ketone 18. Jiannan Xiang and Weimin He of Hunan University prepared (Eur. J. Org. Chem. 2014, 2668) the keto phosphonate 20 by hydrolysis of the alkynyl phosphonate 19. Ken-ichi Fujita of the National Institute of Advanced Industrial Science and Technology cyclized (Tetrahedron Lett. 2014, 55, 3013) the alkyne 21 with CO₂, leading to 22.

Best Synthetic Methods: Functional Group Transformation

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Secondary Alcohol ◽  
Indian Institute ◽  
Chemical Technology ◽  
Synthetic Methods ◽  
Acid Oxidation ◽  
Dimethyl Phosphite ◽  
Benzyl Ethers ◽  
Radical Reduction ◽  
Institute Of Technology ◽  
The University

François Morvan of the Université de Montpellier, using the inexpensive dimethyl phosphite, optimized (Tetrahedron Lett. 2008, 49, 3288) the free radical reduction of 1 to 2. Pawan K. Sharma of Kurukshetra University found (Tetrahedron Lett. 2008, 48, 8704) that NaBH4 in the presence of a catalytic amount of RuCl3.xH2 O reduced monosubstituted and disubstituted alkenes, such as 3, to the corresponding alkanes. Note that benzyl ethers were stable to these conditions. Ken Suzuki of Asahi Kasei Chemicals and Shun-Ichi Murahashi of Okayama University of Science established conditions (Angew. Chem. Int. Ed. 2008, 47, 2079) for the oxidation of primary amines such as 5 to oximes. Both ketoximes such as 6 and aldoximes were prepared using this protocol. Primary and secondary alcohols were stable to these conditions. Three noteworthy procedures for the oxidation of an aldehyde to the acid oxidation state were recently reported. Jonathan M. J. Williams of the University of Bath demonstrated (Chem. Commun. 2008, 624) that crotonitrile could serve as the hydrogen acceptor in the oxidation of an aldehyde 7 to the methyl ester 8. Note that isolated alkenes were stable to these conditions. Vikas N. Telvekar the University Institute of Chemical Technology, Mumbai improved (Tetrahedron Lett . 2008, 49, 2213) the oxidative amination of an aldehyde 9 to the nitrile 10. G. Sekar of the Indian Institute of Technology Madras effected (Tetrahedron Lett. 2008, 49, 1083) oxidation of an aldehyde 11 to the acid 12, under conditions that would be expected to not oxidize a primary or secondary alcohol. J. S. Yadav of the Indian Institute of Chemical Technology, Hyderabad observed (Tetrahedron Lett. 2008, 49, 3015) that the activation of a thiophenol 14 with N-chlorosuccimide generated a species that added regioselectively to a ketone 13 to give the thioether 15. Oxidation of the sulfide 15 followed by heating of the resulting sulfoxide would give the enone 16. This appears to be an easily scalable procedure. It is well known that an acid 17 and an amine 18 will condense at elevated temperature to give the amide 20.

Substituted Benzenes: The Gu Synthesis of Rhazinal

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Aryl Halide ◽  
Indian Institute ◽  
University Of California ◽  
University Of Pennsylvania ◽  
Ru Catalyst ◽  
Cu Catalyst ◽  
Institute Of Technology ◽  
The University ◽  
University Of Manchester ◽  
Structure Of Matter

Sisir K. Mandal of Asian Paints R&T Centre, Mumbai used (Tetrahedron Lett. 2013, 54, 530) a Ru catalyst to couple 2 with an electron-rich arene 1 to give 3. Jun-ichi Yoshida of Kyoto University (J. Am. Chem. Soc. 2013, 135, 5000) and John F. Hartwig of the University of California, Berkeley (J. Am. Chem. Soc. 2013, 135, 8480) also reported direct amination protocols. Tommaso Marcelli of the Politecnico di Milano and Michael J. Ingleson of the University of Manchester effected (J. Am. Chem. Soc. 2013, 135, 474) the electrophilic borylation of the aniline 4 to give 5. The regioselectivity of Ir-catalyzed borylation (J. Am. Chem. Soc. 2013, 135, 7572; Org. Lett. 2013, 15, 140) is complementary to the electrophilic process. Professor Hartwig carried (Angew. Chem. Int. Ed. 2013, 52, 933) the borylated product from 6 onto Ni-mediated coupling to give the alkylated product 7. Weiping Su of the Fujian Institute of Research on the Structure of Matter devised (Org. Lett. 2013, 15, 1718) an intriguing Pd-mediated oxidative coupling of nitroethane 9 with 8 to give 10. The coupling is apparently not proceeding via nitroethylene. Peiming Gu of Ningxia University developed (Org. Lett. 2013, 15, 1124) an azide-based cleavage that converted the aldehyde 11 into the formamide 13. Zhong-Quan Liu of Lanzhou University showed (Tetrahedron Lett. 2013, 54, 3079) that an aromatic carboxylic acid 14 could be oxidatively decarboxylated to the chloride 15. Gérard Cahiez of the Université Paris 13 found (Adv. Synth. Catal. 2013, 355, 790) mild Cu-catalyzed conditions for the reductive decarboxylation of aromatic carboxylic acids, and Debabrata Maiti of the Indian Institute of Technology, Mumbai found (Chem. Commun. 2013, 49, 252) Pd-mediated conditions for the dehydroxymethylation of benzyl alcohols (neither illustrated). Pravin R. Likhar of the Indian Institute of Chemical Technology prepared (Adv. Synth. Catal. 2013, 355, 751) a Cu catalyst that effected Castro-Stephens coupling of 16 with 17 at room temperature. Arturo Orellana of York University (Chem. Commun. 2013, 49, 5420) and Patrick J. Walsh of the University of Pennsylvania (Org. Lett. 2013, 15, 2298) showed that a cyclopropanol 20 can couple with an aryl halide 19 to give 21.

Enantioselective Construction of Alkylated Centers: The Rawal Synthesis of (+)-Fornicin C

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Primary Amine ◽  
Claisen Rearrangement ◽  
Conjugate Addition ◽  
Keto Ester ◽  
Princeton University ◽  
Saturated Aldehyde ◽  
Leaving Group ◽  
Cu Catalyst ◽  
University Of Bristol ◽  
The University

Kazuaki Kudo of the University of Tokyo showed (Angew. Chem. Int. Ed. 2013, 52, 11585) that the dienyl aldehyde 1 could be reduced to the saturated aldehyde 2 with high ee. Alexandre Alexakis of the University of Geneva effected (Angew. Chem. Int. Ed. 2013, 52, 12701) conjugate addition to the unsaturated amide 3 to give 4 in high ee. Professor Alexakis also carried out (Chem. Eur. J. 2013, 19, 11352) enantioselective conjugate addition to the alkynyl nitro alkene 5, leading to 6. Gerrit J. Poelarends of the University of Groningen found (Chem. Eur. J. 2013, 19, 14407) that the enzyme 4-oxalocrotonate tautomerase mediated the conjugate addition of acetaldehyde to a nitroalkene 7 to deliver the aldehyde 8 in high ee. Tohru Yamada of Keio University developed (Chem. Commun. 2013, 49, 8371) an enantioselective Cu catalyst for the Claisen rearrangement of 9 to 10. Shi-Kai Tian of USTC Hefei made (Chem. Commun. 2013, 49, 8190) the primary amine of 11 a leaving group, coupling 11 with 12 to make 13. David W. C. MacMillan of Princeton University alkylated (J. Am. Chem. Soc. 2013, 135, 11756) the aldehyde 14 with the boronic acid 15, to give 16 in high ee. Paolo Melchiorre of ICIQ Tarragona effected (Nature Chem. 2013, 5, 750) the enantioselective construction of the quaternary cen­ter of 19 by alkylation of the aldehyde 17 with 18. Other methods for the enantioselective construction of quaternary alkylated cen­ters have also been put forward. Varinder K. Aggarwal of the University of Bristol elaborated (J. Am. Chem. Soc. 2013, 135, 16054) the inexpensive secondary ester 20 into the alkylated product 21. Jianwei Sun of the Hong Kong University of Science and Technology cyclized (Angew. Chem. Int. Ed. 2013, 52, 13593) the prochiral diol 22 to 23 in high ee. Amir H. Hoveyda of Boston College effected (Angew. Chem. Int. Ed. 2013, 52, 8156) enantioselective conjugate addition to the enone 24 to give 25. Xiaoming Feng of Sichuan University devised (Angew. Chem. Int. Ed. 2013, 52, 10883) a catalyst for the addition of the bulky α-diazo ester 26 into the α-keto ester 27, leading to 28.

Voices After Disaster

2021 ◽  
Author(s):  
Roger Few ◽  
Mythili Madhavan ◽  
Narayanan N.C. ◽  
Kaniska Singh ◽  
Hazel Marsh ◽  
...  
Keyword(s):  
Indian Institute ◽  
Community Members ◽  
Policy And Practice ◽  
Group Discussions ◽  
East Anglia ◽  
Other Information ◽  
The Media ◽  
Institute Of Technology ◽  
The University ◽  
Disaster Narratives

This document is an output from the “Voices After Disaster: narratives and representation following the Kerala floods of August 2018” project supported by the University of East Anglia (UEA)’s GCRF QR funds. The project is carried out by researchers at UEA, the Indian Institute for Human Settlements (IIHS), the Indian Institute of Technology (IIT), Bombay, and Canalpy, Kerala. In this briefing, we provide an overview of some of the emerging narratives of recovery in Kerala and discuss their significance for post-disaster recovery policy and practice. A key part of the work was a review of reported recovery activities by government and NGOs, as well as accounts and reports of the disaster and subsequent activities in the media and other information sources. This was complemented by fieldwork on the ground in two districts, in which the teams conducted a total of 105 interviews and group discussions with a range of community members and other local stakeholders. We worked in Alleppey district, in the low-lying Kuttanad region, where extreme accumulation of floodwaters had been far in excess of the normal seasonal levels, and in Wayanad district, in the Western Ghats, where there had been a concentration of severe flash floods and landslides.

Transition Metal Catalyzed Construction of Carbocyclic Rings: (-)-Hamigeran B

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Allylic Oxidation ◽  
Cyclic Enones ◽  
Peking University ◽  
Cu Catalyst ◽  
Rh Catalyst ◽  
Queen's University ◽  
Carbocyclic Rings ◽  
Metal Catalyzed ◽  
The University ◽  
Cyclic Alkenes

Several elegant methods for the enantioselective transformation of preformed prochiral rings have been put forward. Derek R. Boyd of Queen’s University, Belfast devised (Chem. Commun. 2008, 5535) a Cu catalyst that effected allylic oxidation of cyclic alkenes such as 1 with high ee. Christoph Jaekel of the Ruprecht-Karls-Universität Heidelberg established (Adv. Synth. Cat. 2008, 350, 2708) conditions for the enantioselective hydrogenation of cyclic enones such as 3. Marc L. Snapper of Boston College developed (Angew. Chem. Int. Ed. 2008, 47, 5049) a Cu catalyst for the enantioselective allylation of activated cyclic enones such as 5. Alexandre Alexakis of the University of Geneva showed (Angew. Chem. Int. Ed. 2008, 47, 9122) that dienones such as 8 could be induced to undergo 1,4 addition, again with high ee. Tsutomu Katsuki of Kyushu University originated (J. Am. Chem. Soc. 2008, 130, 10327) an Ir catalyst for the addition of diazoacetate 11 to alkenes such as 10 to give the cyclopropane 12 with high chemo-, enantio- and diastereoselectivity. Weiping Tang of the University of Wisconsin found (Angew. Chem. Int. Ed. 2008, 47, 8933) a silver catalyst that rearranged cyclopropyl diazo esters such as 13 to the cyclobutene 14 with high regioselectivity. Zhang-Jie Shi of Peking University demonstrated (J. Am. Chem. Soc. 2008, 130, 12901) that under oxidizing conditions, a Pd catalyst could cyclize 15 to 16. Sergio Castillón of the Universitat Rovira i Virgili, Tarragona devised (Organic Lett. 2008, 10, 4735) a Rh catalyst for the enantioselective cyclization of 17 to 18. Virginie Ratovelomanana-Vidal of the ENSCP Paris and Nakcheol Jeong of Korea University established (Adv. Synth. Cat. 2008, 350, 2695) conditions for the enantioselective intramolecular Pauson-Khand cyclization of 19 to give, after hydrolysis, the cyclopentenone 20. Quanrui Wang of Fudan University, Several elegant methods for the enantioselective transformation of preformed prochiral rings have been put forward. Derek R. Boyd of Queen’s University, Belfast devised (Chem. Commun. 2008, 5535) a Cu catalyst that effected allylic oxidation of cyclic alkenes such as 1 with high ee.

New Methods for C-N Ring Construction

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
New York ◽  
Gold Complex ◽  
Cascade Process ◽  
State University ◽  
University Of Alberta ◽  
Cornell University ◽  
University Of New Mexico ◽  
Memory Of Chirality ◽  
Cu Catalyst ◽  
The University

Chaozhong Li of the Shanghai Institute of Organic Chemistry demonstrated (Organic Lett. 2008, 10, 4037) facile and selective Cu-catalyzed β-lactam formation, converting 1 to 2. Paul Helquist of the University of Notre Dame devised (Organic Lett. 2008, 10, 3903) an effective catalyst for intramolecular alkyne hydroamination, converting 3 into the imine 4. Six-membered ring construction worked well also. Jon T. Njardarson of Cornell University found (Organic Lett. 2008, 10, 5023) a Cu catalyst for the rearrangement of alkenyl aziridines such as 5 to the pyrroline 6. Philippe Karoyan of the UPMC, Paris developed (J. Org. Chem. 2008, 73, 6706) an interesting chiral auxiliary directed cascade process, converting the simple precursor 7 into the complex pyrrolidine 9. Sherry R. Chemler of the State University of New York, Buffalo devised (J. Am. Chem. Soc. 2008, 130, 17638) a chiral Cu catalyst for the cyclization of 10, to give 12 with substantial enantiocontrol. Wei Wang of the University of New Mexico demonstrated (Chem. Commun. 2008, 5636) the organocatalyzed condensation of 13 and 14 to give 16 with high enantio- and diastereocontrol. Two complementary routes to azepines/azepinones have appeared. F. Dean Toste of the University of California, Berkeley showed (J. Am. Chem. Soc. 2008, 130, 9244) that a gold complex catalyzed the condensation of 17 and 18 to give 19. Frederick G. West of the University of Alberta found (Organic Lett. 2008, 10, 3985) that lactams such as 20 could be ring-expanded by the addition of the propiolate anion 21. Takeo Kawabata of Kyoto University extended (Organic Lett . 2008, 10, 3883) “memory of chirality” studies to the cyclization of 23, demonstrating that 24 was formed in high ee. Paul V. Murphy of University College Dublin took advantage (Organic Lett . 2008, 10, 3777) of the well-known intramolecular addition of azides to alkenes, showing that the intermediate could be intercepted with nucleophiles such as thiophenol, to give the cyclized product 26 with high diastereocontrol.

Practical Enantioselective Construction of Arrays of Stereogenic Centers: The Jørgensen Synthesis of the Autoregulator IM-2

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
University Of Pennsylvania ◽  
Gel Chromatography ◽  
Max Planck ◽  
West Virginia University ◽  
Clemson University ◽  
Stereogenic Centers ◽  
Cu Catalyst ◽  
Enantioselective Epoxidation ◽  
Silica Gel Chromatography ◽  
The University

Armando Córdova of Stockholm University found (Angew. Chem. Int. Ed. 2008, 47, 8468) that the enantiomerically-enriched diastereomers from aminosulfenylation of 1 were readily separable by silica gel chromatography. Benjamin List of the Max-Planck-Institut, Mülheim developed (Angew. Chem. Int. Ed. 2008, 47, 8112) what appears to be a general protocol for the enantioselective epoxidation of enones such as 4. Paolo Melchiorre of the Università di Bologna devised (Angew. Chem. Int. Ed. 2008, 47 , 8703) a related protocol for the enantioselective aziridination of enones. Xue-Long Hue of the Shanghai Institute of Organic Chemistry and Yun-Dong Wu of the Hong Kong University of Science and Technology optimized (J. Am. Chem. Soc. 2008, 130 , 14362) a Cu catalyst for enantioselective Mannich homologation of imines such as 6. Guofu Zhong of Nanyang Technological University, Singapore established (Angew. Chem. Int. Ed. 2008, 47, 10187; Organic Lett. 2008 , 10 , 4585) that enantioselective α-aminoxylation of an ω-alkenyl aldehyde such as 9 could lead to defined arrays of stereogenic centers. George A. O’Doherty of West Virginia University devised (Organic Lett. 2008, 10, 3149) a protocol for the enantioselective hydration of 12 to 13 . René Peters, now at the University of Stuttgart, designed (Angew. Chem. Int. Ed. 2008, 47, 5461) an Al catalyst for the enantioselective combination of an acyl bromide 15 with an aldehyde 14 to deliver the β–lactone 16. Hajime Ito and Masaya Sawamura of Hokkaido University established (J. Am. Chem. Soc. 2008, 130, 15774) that the allenyl borane from 17 added to aldehydes such as 18 with high ee. Keiji Maruoka of Kyoto University developed (Tetrahedron Lett. 2008, 49, 5369) an organocatalyst for the Mannich homologation of an aldehyde such as 20 to 21. R. Karl Dieter of Clemson University showed (Organic Lett. 2008, 10, 2087) that 23, readily prepared in high ee, could be displaced sequentially with two different Grignard reagents, to give 24. Jeffrey W. Bode, now at the University of Pennsylvania, found (Organic Lett. 2008, 10, 3817) that bisulfite adducts such as 25 served well for the addition of unstable chloroaldehydes to 26 to give 27.

Substituted Benzenes: The Saikawa/Nakata Synthesis of Kendomycin

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Alkyl Iodide ◽  
Benzene Derivative ◽  
State University ◽  
One Pot ◽  
Aryl Iodide ◽  
Peking University ◽  
Cu Catalyst ◽  
San Diego State University ◽  
University Of Massachusetts ◽  
The University

Jianbo Wang of Peking University described (Angew. Chem. Int. Ed. 2010, 49, 2028) the Au-promoted bromination of a benzene derivative such as 1 with N-bromosuccinimide. In a one-pot procedure, addition of a Cu catalyst followed by microwave heating delivered the aminated product 2. Jian-Ping Zou of Suzhou University and Wei Zhang of the University of Massachusetts, Boston, observed (Tetrahedron Lett. 2010, 51, 2639) that the phosphonylation of an arene 3 proceeded with substantial ortho selectivity. Yonghong Gu of the University of Science and Technology, Hefei, showed (Tetrahedron Lett. 2010, 51, 192) that an arylpropanoic acid 6 could be ortho hydroxylated with PIFA to give 7. Louis Fensterbank, Max Malacria, and Emmanuel Lacôte of UMPC Paris found (Angew. Chem. Int. Ed. 2010, 49, 2178) that a benzoic acid could be ortho aminated by way of the cyano amide 8. Daniel J. Weix of the University of Rochester developed (J. Am. Chem. Soc. 2010, 132, 920) a protocol for coupling an aryl iodide 10 with an alkyl iodide 11 to give 12. Professor Wang devised (Angew. Chem. Int. Ed. 2010, 49, 1139) a mechanistically intriguing alkyl carbonylation of an iodobenzene 10. This is presumably proceeding by way of the intermediate diazo alkane. Usually, benzonitriles are prepared by cyanation of the halo aromatic. Hideo Togo of Chiba University established (Synlett 2010, 1067) a protocol for the direct electrophilic cyanation of an electron-rich aromatic 15. Thomas E. Cole of San Diego State University observed (Tetrahedron Lett. 2010, 51, 3033) that an alkyl dimethyl borane, readily prepared by hydroboration of the alkene with BCl3 and Et3 SiH, reacted with benzoquinone 17 to give 18. Presumably this transformation could also be applied to substituted benzoquinones. When a highly substituted benzene derivative is needed, it is sometimes more economical to construct the aromatic ring. Joseph P. A. Harrity of the University of Sheffield and Gerhard Hilt of Philipps-Universität Marburg showed (J. Org. Chem. 2010, 75, 3893) that the Co-catalyzed Diels-Alder cyloaddition of alkynyl borinate 21 with a diene 20 proceeded with high regiocontrol, to give, after oxidation, the aryl borinate 22.

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