Kraftwerk is a German band formed in Düsseldorf in 1970 by Ralf Hütter and Florian Schneider. Considered as innovators and pioneers of electronic music, they were among the first successful acts to popularize the genre; the group began as part of West Germany's experimental krautrock scene in the early 1970s before embracing electronic instrumentation, including synthesizers, drum machines, vocoders. On commercially successful albums such as Autobahn, Trans-Europe Express, The Man-Machine, Kraftwerk developed a self-described "robot pop" style that combined electronic music with pop melodies, sparse arrangements, repetitive rhythms, while adopting a stylized image including matching suits. Following the release of Electric Café, member Wolfgang Flür left the group in 1987. Founding member Schneider departed in 2008; the band's work has influenced a diverse range of artists and many genres of modern music, including synthpop, hip hop, post-punk, techno and club music. In 2014, the Recording Academy honoured Kraftwerk with a Grammy Lifetime Achievement Award.
Their latest album 3-D The Catalogue was released in 2017. As of 2019, the remaining members of the band continue to tour. Florian Schneider and Ralf Hütter met as students at the Robert Schumann Hochschule in Düsseldorf in the late 1960s, participating in the German experimental music and art scene of the time, which Melody Maker jokingly dubbed "krautrock", they joined a quintet known as Organisation, which released one album, Tone Float in 1969, issued on RCA Records in the UK, split shortly thereafter. Schneider became interested in synthesizers, deciding to acquire one in 1970. While visiting an exhibition in their hometown about visual artists Gilbert and George, they saw "two men wearing suits and ties, claiming to bring art into everyday life; the same year, Hütter and Schneider started bringing everyday life into art and form Kraftwerk". Early Kraftwerk line-ups from 1970 to 1974 fluctuated, as Hütter and Schneider worked with around a half-dozen other musicians during the preparations for and the recording of three albums and sporadic live appearances, most notably guitarist Michael Rother and drummer Klaus Dinger, who left to form Neu!
The only constant figure in these line-ups was Schneider, whose main instrument at the time was the flute. Hütter, who left the band for eight months to focus on completing his university studies, played synthesizer and keyboards; the band released two free-form experimental rock albums and Kraftwerk 2. The albums were exploratory musical improvisations played on a variety of traditional instruments including guitar, drums, organ and violin. Post-production modifications to these recordings were used to distort the sound of the instruments audio-tape manipulation and multiple dubbings of one instrument on the same track. Both albums are purely instrumental. Live performances from 1972 to 1973 were made as a duo, using a simple beat-box-type electronic drum machine, with preset rhythms taken from an electric organ; these shows were in Germany, with occasional shows in France. In 1973, Wolfgang Flür joined the group for rehearsals, the unit performed as a trio on the television show Aspekte for German television network ZDF.
With Ralf und Florian, released in 1973, Kraftwerk began to rely more on synthesizers and drum machines. Although entirely instrumental, the album marks Kraftwerk's first use of the vocoder, which would in time become one of its musical signatures. According to English music journalist Simon Reynolds, Kraftwerk were influenced by what he called the "adrenalized insurgency" of Detroit artists of the late'60s MC5 and the Stooges; the input and influence of producer and engineer Konrad "Conny" Plank was significant in the early years of Kraftwerk. Plank worked with many of the other leading German electronic acts of that time, including members of Can, Neu!, Harmonia. As a result of his work with Kraftwerk, Plank's studio near Cologne became one of the most sought-after studios in the late 1970s. Plank coproduced the first four Kraftwerk albums; the release of Autobahn in 1974 saw Kraftwerk moving away from the sound of its first three albums. Hütter and Schneider had invested in newer technology such as the Minimoog and the EMS Synthi AKS, helping give Kraftwerk a newer, "disciplined" sound.
Autobahn would be the last album that Conny Plank would engineer. After the commercial success of Autobahn in the US, where it peaked at number 5 in the Billboard Top LPs & Tapes, Hütter and Schneider invested in updating their studio, thus lessening their reliance on outside producers. At this time the painter and graphic artist Emil Schult became a regular collaborator, designing artwork, cowriting lyrics, accompanying the group on tour; the year 1975 saw a turning point in Kraftwerk's live shows. With financial support from Phonogram Inc. in the US, they were able to undertake a multi-date tour to promote the Autobahn album, a tour which took them to the US, Canada and the UK for the first time. The tour saw a new, live line-up in the form of a quartet. Hütter and Schneider continued playing keyboard synthesizers such as the Minimoog and ARP Odyssey, with Schneider's use of flute diminishing; the pair started singing live for the first time, Schneider processing his voice with a vocoder live.
In organic chemistry, the Keck asymmetric allylation is a chemical reaction that involves the nucleophilic addition of an allyl group to an aldehyde. The catalyst is a chiral complex that contains titanium as a Lewis acid; the chirality of the catalyst induces a stereoselective addition, so the secondary alcohol of the product has a predictable absolute stereochemistry based on the choice of catalyst. This name reaction is named for Gary Keck; the Keck asymmetric allylation has many applications to the synthesis of natural products, including -Gloeosporone, Epothilone A, the CD-Subunit of spongistatins, the C10-C20 Subunit of rhizoxin A, The Keck allylation has been utilized to form substituted tetrahydropyrans enantioselectively, moieties found in products such as phorboxazole and bryostatin 1. Although the groups of E. Tagliavini and K. Mikami reported the catalysis of this reaction using a Ti–BINOL complex in the same year as the Keck group, Keck's publication reported higher enantio- and diastereoselectivity, did not require the use of 4 Angstrom molecular sieves as in Mikami's procedure or an excess of BINOL as in Tagliavini's procedure.
Keck's early success with stereoselectivity and the simplicity of the catalyst preparation led to many improvements in reaction design, including development of other structural analogs of BINOL, use of stoichiometric additives to enhance the reaction rate, broadening the scope of the reaction to include substituted stannane nucleophiles. The mechanism of this allylation is not known, although a cycle involving activation of the aldehyde by the bidentate BINOL-Ti complex followed by the addition of the allyl ligand to the aldehyde, removal of the tributyltin, transmetallation to regenerate the Ti complex has been proposed. Work performed by Keck and followed up by Faller and coworkers showed a positive nonlinear effect correlating the product enantiomeric purity with the BINOL enantiomeric purity; these observations imply that a dimeric meso-chiral catalyst is less active than the homochiral dimers, leading to the observed chiral amplification. Corey and coworkers established a CH-O hydrogen bonding model that accounts for the absolute stereochemistry of the transformation.
The Tagliavini group, which had carried out asymmetric allylation using a similar BINOL-Ti complex, followed up early successes by synthesizing a variety of enantiopure substituted binaphthyl ligands. The most successful of these substituted binaphthyls, shown below, gave 92% product enantiomeric excess in the addition of allyltributyltin to aldehydes with a Ti2Cl2 metal complex; the Brenna group developed a synthesis for a binol analog, shown below, which can be resolved into its enantiomers quite and used as a chiral auxiliary for stereoselective Keck allylations, showing in some cases improved enantiomeric excesses of up to 4% over the -BINOL catalyzed allylations. Additionally, the developed auxiliary showed an NLE similar to the classic BINOL, allowing enantio-impure quantities to be used. Faller's group, whose aforementioned work helped elucidate the chiral amplification of the reaction developed the use of diisopropyl tartrate in a chiral poisoning strategy. Diisopropyl tartrate, racemic BINOL, Ti4, allyltributyltin were used to give enantiomeric excesses of up to 91%.
Yoshida and coworkers developed a synthesis of dendritic binaphthols that serve as homogenous recoverable catalyst systems, showed that they were amenable to forming homoallylic alcohols using Keck's allylation conditions. Maruoka and Kii developed a bidentate Ti binol ligand for the allylation of aldehydes with the aim of restricting M-O bond rotation between the lewis acid and the aldehyde in order to improve enantiomeric excesses; the bidentate ligand contains two titaniums, an aromatic diamine connecting moiety, gave enantiomeric excesses of up to 99%. Improved stereoselectivity is proposed to come from double activation of the carbonyl from the titaniums, a hypothesis supported by C13 NMR and IR spectroscopy studies on 2,6-γ-pyrone substrate; the most convincing evidence that the M-O rotation is restricted comes from NOE NMR studies on trans-4-methoxy-3-buten-2-one. Radiation of methoxyvinyl protons in free enone and in enone complexed with monodentate Ti show s-cis and s-trans conformations, while radiation of the enone in a bidentate Ti complex showed predominantly s-trans conformers.
In 2003, this group extended the allylation strategy using this bidentate catalyst to ketones. Two key steps in the allylation reaction involve breakage of the Sn-C bond in the allyl fragment and formation of the O-Sn bond to facilitate reproduction of the Ti catalyst. Chan Mo-Yu and coworkers developed an alkylthiosilane accelerator to promote both of these steps increasing the reaction rate and lowering the required catalyst dosages. Coupling of phenylaldehyde with allyltributyltin afforded 91% yield and 97% enantiomeric excess of homoallylic alcohol using 10 mol% of the BINOL-Ti catalyst, however addition of the alkylthiosilane and use of only 5 mol% catalyst gave 80% yield and 95% enantiomeric excess of homoallylic alcohol. Brueckner and Weigand extended the use of this allylation chemistry to beta-substituted stannanes, including those that contain heterocycles, in 1996, exploring a variety of titanium alkoxides, premixing times, reaction temperatures; the optimal discovered conditions were 10 mol% Ti4 or Ti4, 20 mol% enantiopure BINOL, with a premixing period of 2 hours, giving enantiomeric excesses of up to 99%
Xavier Di Petta is an Australian Music Producer, Internet Entrepreneur, a creator of EarthPix and HistoryInPics. Di Petta has been featured in The Times"Top 25 Under 20' and'The 15 Smartest Teens on the Planet'. Di Petta has amassed followings. Di Petta is a Partner at MedSpa Advertising in Beverly Hills, CA, the fastest growing ad agency in North America for medical aesthetic clinics. Di Petta was born and raised in Shepparton, Victoria, a small Australian town two hours north of Melbourne. At six, he represented Australia in the Nintendo World Championships. Di Petta attended the University of Southern California, where he was a member of Society53. In 2009, Di Petta "found email addresses for YouTube staffers in a lawsuit document and contacted them directly about a new program that allowed him to make money from his videos."In 2012, Di Petta created Fitspiration, designed to help users keep motivated about fitness. The application was the number-one fitness application in the United States and New Zealand, among others.
Di Petta's firm, Swift Fox Labs, works with brands such as GE and Nike. In July 2013, Di Petta created @EarthPix and @HistoryInPics on Twitter with Kyle Cameron; as of September 2016, the accounts have 1.91 3.48 M followers, respectively. @EarthPix on Instagram has over 14M followers and is ranked the 113th Most Followed Instagram account. At 17, Di Petta co-founded Social Trends Media. Social Trends Media earned $800,000 in sales in December 2013. In May 2014, Di Petta was featured in a Special Interest Paper by the City of London on'Cultural Innovation and Entrepreneurship in London'In October 2014, Di Petta joined the Advisory Board of the National Women's History Museum, along with Gloria Steinem and Jenna Bush. Di Petta has curated for Condé Nast, including GQ and LOVE. In December 2014, All Day Media raised $2,000,000 from investors including Upfront Ventures, 500 Startups and Daher Capital. Di Petta was a speaker at TEDxTeen NYC in May 2015. Di Petta worked with WWF and W+K to launch their #EndangeredEmoji Campaign